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Volume 88, 1960-61
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Studies on Australian and New Zealand Diatoms
V.—The Rawson Collection of Recent Diatoms

Prepared for Publication by E. J. Ferguson Wood

*

[Received by the Editor, November 19, 1959.]

Abstract

The, S. H. Rawson Collection consists of 272 slides of recent diatoms collected in and around Dunedin. The material was mounted and identified by the late Mr. Rawson, and is now the property of the University of Otago. As Mr. Rawson did not publish his work, the author has prepared it for publication, and has taken the opportunity to describe those species which are new records for Australasia. A new Actinoptychus and a Triceratium were identified, but the latter has only one valve.

Introduction

The, S. H. Rawson Collection consists of 272 slides of recent diatoms from the Dunedin area, and 475 slides of fossil diatoms from Otago Province. These slides were prepared, and the species named, by Mr. Rawson, and the collection is now the property of the Botany Department of the University of Otago. Unfortunately Mr. Rawson did not publish his work, and the author was asked by Professor G. T. S. Baylis to examine the slides and prepare the material for publication in order to increase the knowledge of the flora of Otago, and to make the Rawson Collection of greater use to diatomists and to teachers and students in New Zealand. This has now been done, and one must praise the care with which the material was prepared and mounted, and the identifications made I have been able, with some outside assistance, notably from Mr. N. Ingram Hendey, to identify several species that Mr. Rawson could not.

In order to give as complete a picture as possible of the diatom flora of Australasia, I have included in this paper descriptions and illustrations of those species which have not been described in previous parts of this series, but have merely listed in this paper the species which have previously been described therein. Under each of these is given a reference to the part of this series in which the description and figure appear.

List of Species Recorded

Sub-Order Discineae
Family Coscinodiscaceae
Genus Melosira Agh., 1824

1. Melosira roeseana Rab (Slides 100, 219) (Pl. 57, Fig. 1)

  • Rab., 1853, 13.

  • Boyer, 1916, 1, 5, 1927, 27.

Cells usually in short chains; frustule furnished with coarse longitudinal striae; valves convex, with fine punctate striae, radiating and becoming faint towards the centre where several large granules or spines are evident. Diameter, 10–40μ

Distribution Bruce's Rocks (Dunedin).

2. Melosira sulcata (Ehr.) Kütz. (Slides 268, 269), (see Part I)

Distribution. Hooper's Inlet.

Genus Hyalodiscus Ehr., 1845

[Footnote] * C. S. I. R. O. Division of Fisheries and Oceanography, Cronulla, Sydney.

– 700 –

3. Hyalodiscus (Podosira) maximums Petit (Slides 111, 115, 133, 142, 148, 208), (Pl. 57, Fig. 2)

  • Petit, 1877, 47.

  • Boyer, 1927, 31.

Cells solitary; valves with or without a central area; interspaces radiating from the centre; surface convex gradually decreasing towards the border, puncta in fine irregular radiating lines; margin striated. Diameter, 80–130μ.

Distribution. Bruce's Rocks. (Petit, 1877).

4. Hyalodiscus pustulatus A. S. (Slide 7), (see Part III)

Distribution. Anderson's Bay.

5. Hyalodiscus subtilis (Slides 224, 230), (see Part III)

Distribution. Evansdale.

Genus Stephanopyxis Ehr., 1844

6. Stephanopyxis turris (Grev. and Arnott) Ralfs (Slide 160), (see Part I)

Distribution. Company Bay (Otago Harbour).

Genus Coscinodiscus Ehr., 1838

7. Coscinodiscus centralis Ehr. (Slide 72), (see Part I)

Distribution. Company Bay.

8. Coscinodiscus lineatus Ehr. (Slide 178), (see Part I)

Distribution. Bruce's Rocks.

9. Coscinodiscus nitidus Grun. (Slides 131, 259), (see Part III)

Distribution. Bruce's Rocks.

10. Coscinodiscus lacustris Grun. (Slides 226, 231), (see Part III)

Distribution. Hooper's Inlet.

11. Coscinodiscus gigas Ehr. (Slides 71, 126, 195, 196, 201), (see Part I)

Distribution. Company Bay, Bruce's Rocks.

12. Coscinodiscus radiatus Ehr. (Slide 44), (see Part I)

Distribution. Smith's Bay (Otago Harbour)

Genus Cyclotella Kütz, 1833

13. Cyclotella stelligera Cl. & Grun. (Slides 86, 87) (see Part II)

Distribution. Waitati, Anderson's Bay.

Family Actinodiscaceae
Genus Actinoptychus Ehr., 1839

14. Actinoptychus vulgaris Schumann (Slides 39, 90, 105, 106, 119, 135), (Plate 57, Fig. 3)

  • Schum, 1867, 64.

  • A.S. Atl., 1891, 132, 6, 7, 17; 153, 1.

Cells solitary; valves discoid, with 12 to 16 sectors, central area more or less circular; sectors with spines, on each side of the spine two definite hyaline markings; valve surface of coarse areolae and oblique decussating striae Diameter, 80—130μ

Distribution. Smith's Bay, Bruce's Rocks, Goat Island.

15. Actionoptychus sp (Slide 144), (Plate 57, Fig. 4)

Cells solitary, discoid; valves undulate, with broad and narrow segments alternating; central area hyaline with ring of puncta from which originate about 10 narrow rays, the puncta of which are interconnected by a meshwork, inner layer finely areolate. Diameter, 100μ

Distribution. Bruce's Rocks.

– 701 –

16. Actinoptychus senarius (Ehr.) Ehr. (Slides 12, 43, 110), (see Part I)

Distribution. Anderson's Bay, Smith's Bay, Goat Island.

Genus Actinocyclus Ehr., 1837

17. Actinocyclus barklyi (Coates) var. aggregatus Ratt. (Slides 27, 99, 137, 181, 184, 209), (Plate 57, Fig. 5)

I consider this species a synonym of A. octonaria Ehr. (Part IV).

Distribution. Anderson's Bay, Brighton, Bruce's Rocks.

18. Actinocyclus moniliformis Ralfs (Slides 107–9), (Plate 57, Fig. 6)

I consider this species a synonym of A. octonaria Ehr. (Part IV).

Distribution. Goat Island.

19. Actinocyclus ehrenbergii Ralfs (Slides 22, 55, 101, 153, 254)

I consider this form identical with Actinocyclus moniliformis Ralfs, A. octonaria Ehr. (Part IV)

Distribution. Portobello, Bruce's Rocks, Kakanui Beach.

Genus Cosmiodiscus

20. Cosmiodiscus elegans Grev. (see Part III)

Distribution. Anderson's Bay.

Genus Aulacodiscus Ehr., 1844: em. Ratt., 1888

21. Aulacodiscus kittoni var. johnsonii (Arnott) Ratt. (Slides 62, 128, 145, 151, 213, 215), (Plate 57, Fig. 7)

  • Ratt., 1888, 376.

  • Aulacodiscus johnsonii Arnott in Pritch., 1861, 844.

Cells solitary, discoid; valve surface with 4 to 5 processes, rarely less, sculpture of crowded polygonal granules becoming more numerous as they proceed outwards, giving a forked appearence; central area round to angular, from processes to margin more or less striate.

Distribution. Smith's Bay, St. Clair Beach, Bruce's Rocks.

22. Aulacodiscus brownei Norman in Pritch. (Slide 199), (Plate 57, Fig. 8)

  • Norman, Ralfs in Pritch, 1861, 844.

  • Boyer, 1927, 76

  • Aulacodiscus probabilis A. S. 1875, p. 36, f. 15; pl. 105, f. 6.

Cells solitary, discord; valve surface with 2 to 4 processes, about one-third inside the margin; central area irregular, broad, hyaline; sculpture irregular at the centre, more uniform towards the margin, a clear space at the base of each process.

Distribution. Portobello.

23. Aulacodiscus beeveriae Johnson (Slides 20, 40, 41, 89, 117, 140, 147, 182), (see Part I)

Distribution. Anderson's Bay, Bruce's Rock, Smith's Bay.

Family Biddulphiaceae
Genus Biddulphia Gray, 1821

24. Biddulphia aurita (Lyngb.) Breb. (Slides 68, 75, 266), (see Part I)

Distribution. Portobello, Company Bay, Hooper's Inlet.

25. var. obtusa (Kütz.) Hust. (Slides 168, 174), (see Part III)

Distribution. Bruce's Rock.

26. Biddulphia pulchella Gray (Slides 120, 127, 130, 152, 161), (see Part I)

Distribution. Bruce's Rocks.

27. Biddulphia reticulata Roper (Slides 53, 102, 118, 143, 172, 175, 176, 188), (see Part I)

Distribution. Bruce's Rocks, Kakanui Beach.

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28. Biddulphia turgida (Ehr.) W. Sm. (Slides 36, 94, 104), (see Part I)

Distribution. Bruce's Rocks, Smith's Bay.

29. Biddulphia reticulata Roper var. rawsonii var. nov (Slides 177 (type), 164), (Plate 57, Fig. 9; photo of type specimen)

Cells in chains; processes and sculpture as of type; valves elliptic-lanceolate, connecting zone in valve view quadrate.

Cellae catenatae; gibberi et proplasma typici; valvae subovatae; cingulum quadratum.

Distribution. Bruce's Rocks.

Genus Triceratium Ehr., 1839

30. Triceratium sp., (Slide 146), (Plate 57, Fig. 10)

Valve triangular, processes robust, surface of finely punctate striae radiating from centre of the cell, at the base of each process, striae in curved radiating lines; spinous; margin appears scalloped. Girdle view not shown.

Distribution Bruce's Rocks.

31. Triceratium alternans Bail. (Slides 56, 252), (see Part I)

Distribution. Portobello.

32. Triceratium favus Ehr. (Slides 37, 58, 136, 150, 185), (see Part I)

Distribution. Smith's Bay, Bruce's Rocks.

33. Triceratium reticulum Ehr. (Slides 28, 52, 92, 116, 171), (see Part I)

Distribution. Smith's Bay, Portobello, Bruce's Rocks.

Family Auliscaceae
Genus Auliscus Ehr., 1843

34. Auliscus sculptus (W. Sm.) Ralfs (Slides 9, 33, 91, 97, 121, 264), (see Part I)

Distribution. Anderson's Bay, Smith's Bay, Hooper's Inlet.

Family Chaetoceraceae
Genus Chaetoceros Ehr., 1844

35. Chaetoceros armatum T. West (Slide 217), (see Part III)

Distribution. Moeraki Beach.

Sub-Order Araphidineae
Family Fragilariaceae
Genus Fragilaria Lyngbye 1819

36. Fragilaria virescens Ralfs (Slide 193), (see Part IV)

Distribution. Bruce's Rocks.

Genus Plagiogramma Grev., 1859

37. Plagiogramma robertsianum Grev. (Slide 207), (Plate 57, Fig. 11)

  • Grev., 1863, 18, 1, 1, 2.

Frustules in girdle view rectangular with slightly raised and rounded apices; valves fusiform, with hyaline ends and middle, surface with transverse striae, finely punctate; pseudo-raphe central, usually clearly visible Length, 40–55μ

Distribution Smith's Bay. (Type loc. Port Stephens, Australia).

Genus Entopyla Ehr. 1848

38. Entopyla australis Ehr. (Slides 54, 125, 132), (see Part III)

Distribution. Kakanui Beach, Bruce's Rocks.

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39. Entopyla ocellata (Arn.) Grun var. pulchella (Arn.) Fricke (Slide 149), (Plate 57, Fig. 12)

  • Fricke, A. S. Atl., 231, 9–11.

  • Eupleura pulchella Arn., 1858, 89.

Valves linear to linear-elliptic, with rounded ends; costae strong, crossed near margin and near axis by longitudinal striae; valves may be curved or nearly flat as in the present specimens.

Distribution. Dunedin.

Genus Dimerogramma Ralfs in Pritch., 1861

40. Dimerogramma minus (Greg.) Ralfs (Slide 163), (Plate 57, Fig. 13)

  • Ralfs in Pritch., 1861, 790.

  • Boyer, 1916, pl. 12, f. 12–14; 1927, 193.

  • Denticula minus Greg. 1857, 21, 495.

Valves linear-elliptic; extremities without puncta; pseudoraphe lanceolate; striae radiate, punctate.

Distribution. Bruce's Rocks.

Genus Rhaphoneis Ehr. 1844.

41. Rhaphoneis surirella (Ehr.) Grun. var. australis Petit (Slides 159, 194), (see Part IV)

Distribution. Bruce's Rocks.

42. Rhaphoneis belgica Grun. (Slide 112), (Plate 57, Fig. 14)

  • Grun. in v H. 1881, 36.

  • Boyer, 1927, 190.

Valves lanceolate, narrow, ends produced; striae transverse, slightly radiating, punctate, puncta in straight longitudinal lines. Length, 65μ.

Distribution. Bruce's Rocks.

Genus Synedra Ehr., 1830

43. Synedra vaucheriae Kütz. (Slide 261), (Plate 57, Fig. 15)

  • Kütz, 1844, 65.

  • Boyer, 1927, 200.

  • A. S. 1914, 305, 18–31.

Valves lanceolate, may be rostrate at the extremities; striae transverse; pseudonodule eccentric.

Distribution. Hooper's Inlet.

44. Synedra fulgens (Grev.) W. Sm. (Slide 23), (see Part IV)

Distribution. Anderson's Bay.

45. Synedra ulna (Nitzsch) Ehr. (Slide 156), (see Part II)

Distribution. Bruce's Bay.

46. Synedra undulata (Bail) Greg. (Slides 198, 262), (see Part II)

Distribution. Portobello.

Genus Trachysphenia Petit, 1877

47. Trachysphenia australis Petit (Slide 162), (see Part IV)

Distribution. North East Harbour.

Genus Grammatophora Ehr., 1839

48. Grammatophora marina (Lyngb.) Kütz (Slide 170), (see Part II)

Distribution. Bruce's Rocks.

Genus Rhabdonema Kütz. 1844

49. Rhabdonema minutum Kütz (Slide 169), (Plate 57, Fig. 16a, b)

  • Kütz., 1844, 126.

  • Boyer, 1916, pl. 8, f. 7; pl. 38, f. 11; 1927, 150.

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Frustules in ribbon-like chains; oblong; septa marginal, alternate; valves elliptic-lanceolate, with transverse striae.

Distribution. Bruce's Rocks.

Genus Terpsinoe Ehr., 1843

50. Terpsinoe americana (Bail.) Ralfs (Slide 260), (see Part IV)

Distribution. Hooper's Inlet.

Sub-Order Monoraphidineae
Family Achnanthaceae
Genus Achnanthes Bory, 1822

51. Achnanthes longipes Ag. (Slide 50), (see Part II)

Distribution. Portobello.

52. Achnanthes brevipes Ag. (Slide 64), (see Part II)

Distribution. Anderson's Bay.

53. Achnanthes inflata (Kütz.) Grun. (Slide 65), (see Part IV)

Distribution. Anderson's Bay.

Genus Cocconeis Ehr., 1838, em. Grun., 1868

54. Cocconeis saint paulii Heiden & Kolbe (Slide 129), (Plate 57, Fig. 17a, b, c)

  • Heiden and Kolbe, 1928, 588, 35, 110, 110a.

  • C. sublittoralis Hendey, 1915, 45, pl. 13, 1–9.

Cells solitary; valves dissimilar, broadly oval with rounded extremities; upper valve with a weakly eccentric or somewhat irregular pseudoraphe; valve surface areolate, areolae not as large as Hendey's form and much more regular in transverse lines; each apex of the valve furnished with one large areola, both of which are situated on the same side of the pseudoraphe; lower valve flat, with a central raphe and a clear axial area widening towards the centre to form a large circular central area.

Distribution. Bruce's Rocks.

55. Cocconeis scutellum Ehr. (Slides 57, 257), (see Part II)

Distribution. Portobello, Smith's Bay.

56. Cocconeis scutellum var. (Slide 26), (Plate 57, Fig. 18)

Valves elliptical, lower valve with a loculiferous rim and radiate striae; upper valve with coarse moniliform striae ending on the margin in a double row of small puncta.

Distribution. Anderson's Bay.

Genus Campyloneis Grun., 1862

57. Campyloneis grevillei (W. Sm.) Grun. (Slides 103, 122, 141), (see Part IV)

Distribution. Bruce's Rocks, Smith's Bay.

Genus Rhoicosphenia Grun., 1860

58. Rhoicosphenia curvata (Kütz.) Grun. (Slide 173), (see Part IV)

Distribution. Bruce's Rocks.

Sub-Order Biraphidineae
Family Naviculaceae
Genus Navicula Bory 1894

59. Navicula latissima Greg. (Slide II), (Plate 57, Fig. 19)

  • Greg., 1856, 4, 40.

  • Boyer, 1916, pl. 24, f. 3; 1927, 403.

Valves elliptic-lanceolate with acute to subrostrate extremities; median area linear, central area transversely oval; moniliform striae transverse, short marginal striae alternating with the median striae.

Distribution. Anderson's Bay.

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60. Navicula circumsecta (Grun.) Cleve. (Slides 18, 139), (Plate 1, Fig. 20)

  • Cleve, 1895, (2) 27: 58.

  • Boyer, 1927, 413.

Navicula polysticta circumsecta Grun. in A. Schmidt, Jahresber. Komm. Unters. Dtsch. Meere Kiel, (2) 1874, 1, 36. Valves elliptic; marginal striae short, median striae faint.

Distribution. Anderson's Bay, Bruce's Rocks.

61. Navicula hennedyi var. manca A.S. (Slide 59), (Plate 57, Fig. 21)

  • A.S. 1874, 3, 17.

  • Boyer, 1927, 413.

Valves elliptic, striae interrupted by two longitudinal blank spaces, marginal striae, moniliform, transverse, median striae irregular in length, joining with marginal striae at the extremities.

Distribution. Smith's Bay.

62. Navicula crucigera (W. Sm.) Cleve (Slide 66), (Plate 57, Fig. 22)

  • Cleve., 1894, 111.

  • Boyer, 1927, 367.

  • Schizonema cruciger W. Smith, 1856, 2, 74.

Valves linear-lanceolate, striae moniliform, transverse; striae short on margin opposite the central nodule; median area narrow.

Distribution. Anderson's Bay.

63. Navicula scopulorum Breb., ex Kütz. (Slide 76), (Plate 58, Fig. 23)

  • Boyer, 1927, 375.

  • Cl., 1894, 151.

Valves linear, elongated, slightly gibbous in the middle, with rounded, slightly inflated extremities; median area indistinct, central area small; striae of fine moniliform puncta radiate in the middle convergent at the extremities.

Distribution. Waitati.

64. Navicula elegans W. Sm. (Slides 113, 214), (Plate 58, Fig. 24)

  • W. Sm., 1853, 1, 49; 16, 137.

  • Boyer, 1916, pl. 31, f. 2; 1927, 418

  • A. S. Atl., 1934, 393, 2–3.

Valves linear-elliptic, with produced rounded extremities; central area large, orbicular, median area narrow; striae strong, divergent in the central area, convergent at the extremities, curving towards the margin.

Distribution. Bruce's Rocks.

65. Navicula pinnata Pant. (Slide 155), (Plate 58, Fig. 25)

  • Pant., 1889, 2, 54

  • Boyer, 1916, pl. 27, f. 20, 1927, 397.

Valves lanceolate, with acute extremities; median area wider in the middle than at the extremities; striae radiating in the middle, transverse at the ends.

Distribution. Bruce's Rocks.

66. Navicula tumida Breb. ex Kütz. (Slide 229), (Plate 57, Fig. 26)

  • Kütz., 1849, 77.

  • Boyer, 1927, 375

  • A.S. Atl, 1906, 261, 8–11

Valves lanceolate, with rounded extremities; raphe slightly sigmoid, median area narrow, central area more or less elliptical; striae short, parallel at the extremities, radiate towards the centre of the valve.

Distribution. Evansdale.

67. Navicula pusilla var. subcapitata Boyer (Slide 236), (Plate 57, Fig. 27).

  • Boyer, 1916, 91, 25, 8; 1927, 407.

Valves elliptical, with rostrate-capitate to truncate extremities; striae punctate radiating but unequal in the middle; median area narrow, though wider towards the centre; median fissures incrassate, terminal fissures in the same direction.

Distribution. Evansdale.

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68. Navicula humerosa Breb. ex W. Sm. (Slide 271), (Plate 58, Fig. 28)

  • W. Sm., 1856, 2, 93.

  • Boyer, 1916, pl. 25, f. 5, 1927, 403.

  • A.S. Atl., 1874, 6, 3–4.

Valves oblong-elliptic, or lanceolate-elliptic, with rostrate or sub-cuneate extremities; median area narrow, central area dilated transversely; central pores incrassate and terminal fissures hook-shaped, turned in the same direction; striae radiate, median striae often of unequal length, radiate.

Distribution. Hooper's Inlet.

69. Navicula sulcifera Hustedt var. (Slide 17), (Plate 58, Fig. 29)

  • Hust., 1955, 24, 8, 1.

  • Differs from type (see Part IV) in slightly constricted middle; and slightly capitate ends.

Distribution. Anderson's Bay.

70. Navicula lyra Ehr. (Slides 19, 265), (see Part II)

Distribution. Anderson's Bay, Hooper's Inlet.

71. Navicula lyra var. dilatata A.S. (Slide 17), (see Part IV)

Distribution. Anderson's Bay.

72. Navicula yarrensis Grun. (Slides 31, 250, 267), (see Part II)

Distribution. Hooper's Inlet, Evansdale, Anderson's Bay.

73. Navicula luxuriosa Grev. (Slide 75), (see Part IV)

Distribution. Company Bay.

Genus Diploneis Ehr., 1844, em. Cl., 1894

74. Diploneis constricta (Grun.) Cl. (Slide 114), (see Part IV)

Distribution. Bruce's Rocks.

75. Diploneis fusca (Greg.) Cl. (Slide 16), (see Part II)

Distribution. Anderson's Bay.

76. Diploneis crabro Ehr. (Slide 25), (see Part II)

Distribution. Anderson's Bay.

77. Diploneis crabro var. pandura (Breb.) Cl. (Slides 48, 134), (see Part II)

Distribution. Portobello, Bruce's Rocks.

78. Diploneis smithii (Breb.) Cl. (Slides 47, 245), (see Part II)

Distribution. Portobello, Evansdale.

79. Diploneis smithii f. rhombica Mereschkowsky (Slide 77), (see Part II)

Distribution. Waitati.

Genus Pleurosigma W. Sm., 1852

80. Pleurosigma parkeri Harrison (Slide 166), (Plate 2, Fig. 30)

Harrison, 1860, 104.

Valves lanceolate, broad, sigmoid, extremities produced into obtuse beaks, raphe central, sigmoid; transverse and longitudinal striae.

Distribution. St. Leonards.

81. Pleurosigma rigidum W. Sm. (Slide 30), (Plate 58, Fig. 31)

  • W. Sm., 1853, 1, 64, 20, 198.

  • Boyer, 1927, 474.

Valves linear-lanceolate, slightly sigmoid with rounded extremities; raphe central; striae transverse and oblique.

Distribution. Portobello.

82. Pleurosigma hippocampus (Ehr.) W. Sm. (Slide 5), (Plate 58, Fig. 32)

  • W. Sm., 1853, 1, 68.

  • Cl. & Grun., 1880, (2), 17, 54.

  • Navicula hippocampus Ehr., 1838, 180.

Picture icon

Fig. 1.—Melossia roesena. Fig. 2.—Hyalodiscus (Podosira) maximus. Fig. 3.—Actinoptychus vulgaris. Fig. 4.—Actinoptychus sp. Fig. 5.—Actinocyclus barklyi. Fig. 6.—Actinocyctus monniliformis Fig. 7.—Aulacodiscus var. johnsonii. Fig. 8.—Aulacodiscus broadly. Fig. 9.—Biddulphia reticulata var. rawsonii. Fig. 10.— [ unclear: ] Triceratum sp. Fig. 11.—Plagiogramma robertstanum. Fig. 12.—Entopyla ocellata var. pulchella. Fig. 13.— Dimerogramma minus. Fig. 14.—Rhaphoneis belgica. Fig. 15.—Synedra vaucheriae. Fig. 16, a, b —Rhabdonema minutum. Fig. 17 a, b, c —Cocconeis saintpaulu. Fig. 18.—Cocconeis scutellum var. Fig. 19.— Navicula latissima. Fig. 20.—Navicula circumsecta. Fig. 21.—Navicula hennedyi var. manca. Fig. 22.—Navicula Fig. 26.—Navicula pusilla var. subcapitata.

Picture icon

Fig. 23.—Navicula scopulorum. Fig. 24.—Navicula elegans. Fig. 25.—Navicula pinnata. Fig. 28.—Navicula humerosa. Fig. 29.—Navicula sulcifera. Fig. 30.—Pleurosigma parkeri. Fig. 31.—Pleurosigma rigidum. Fig. 32.—Pleurosigma hippocampus. Fig. 33.—Pleurosigma angulatum var. quadratum. Fig. 34.—Caloneis formosa. Fig. 35.—Caloneis silicula var. inflata. Fig. 36.—Pinnularia cardinaliculus. Fig. 37.—Pinnularia trevelyana. Fig. 38.—Pinnularia nodosa. Fig. 39.—Frustulia weinholdtii. Fig. 40.—Frustulia rhomboides var. amphipleuroides. Fig. 41a, b —Amphiprora alata var. pulchra. Fig. 42.—Epithemia gibberula var. producta. Fig. 43a, b —Epithemia zebra var. proboscidea. Fig. 44.—Epithemia muelleri. Fig. 45.—Cymbella yarrensis. Fig. 46.—Gomphoneis herculaneum. Fig. 47.—Nitzschia acuminata. Fig. 48.—Nitzschia circumsuta. Fig. 49.— Fig. Nitzschia granulata. Fig. Nitzschia. Fig. 50.—Nitzschia tryblionella var. yarrensis. Fig. 54.—surirella filholu. Fig. 55.—surirella contorta.

Picture icon

Fig. 56.—surirella biseriala. Fig. 57. —surirella recedens. Fig. 58. —Campylodiscus incertus. Fig. 59. —Campylodiscus impressus. Fig. 60. —Campylodiscus ralfsii. Fig. 61. —Campylodiscus taentatus. Fig. 62. —surirella conlorta.

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Valves lanceolate, slightly sigmoid, with obtuse ends; raphe sigmoid, central; striae transverse and longitudinal.

Distribution. Anderson's Bay.

83. Pleurosigma angulatum var. quadratum (W. Sm.) V. H. (Slides 8, 96), (Plate 58, Fig. 33)

  • V. H. 1881, pl. 18, fig. 1.

  • Boyer, 1927, 472.

  • Pleurosigma quadratum W. Sm., 1852, 1, 65, 20.

Resembles type but wider and with more angular sides. There is still some doubt as to the authenticity of the Australian and New Zealand forms of Pleurosigma angulatum. As pointed out by N. I. Hendey (in litt.), the southern varieties have not the longitudinal and transverse striae on the extremities as has the northern type, though a vestige of this may occur.

Distribution. Anderson's Bay.

Genus Caloneis Cl, 1894

84. Caloneis formosa (Greg.) Cl. (Slides 223, 243), (Plate 58, Fig. 34)

  • Cl. 1894, 57. Boyer, 1916, 21, pl. 21, f. 18; 1927; 314.

  • A.S. Atl., 1875, 50, 10, 12–15

  • Navicula formosa Greg. 1856, 4, 42.

Valves lanceolate, with obtuse or sub-cuneate extremities; axial area lanceolate, somewhat unilateral, and dilated at the valve centre; striae slightly radiate, punctate; longitudinal lines more or less parallel to the margin.

Distribution. Evansdale.

85. Caloneis silicula var. inflata (Grun.) Cl. (Slide 270), (Plate 58, Fig. 35)

  • Cl. 1894, 51.

  • Boyer, 1916, pl. 21, f. 4; 1927, 308.

  • Navicula limosa inflata Grun. 1860, 10, 5, 8c.

Valves linear, gibbous in the middle, with broad rounded ends; central area elliptical; striae transverse, finely punctate, longitudinal lines parallel to the margin.

Distribution. Hooper's Inlet.

86. Stauroneis phoenicenteron (Nitzsch) Ehr. (Slides 78, 221), (see Part II and Part IV)

Distribution. Waitati, Milford, Temuka.

87. Stauroneis fulmen var. capitata Heid. (Slide 157,), (see Part IV)

Distribution. Wellington, Bruce's Rocks.

88. Stauroneis anceps Ehr. (Slides 158, 167, 237), (see Part II)

Distribution. Bruce's Rocks, St. Leonards, Evansdale.

Genus Pinnularia Ehr. em Cl., 1895

89. Pinnularia cardinaliculus Cl. (Slide 13), (Plate 58, Fig. 36)

  • Cl., 1895, 79.

  • Boyer 1916, pl 30, fl; 1927, 436.

Valves linear with rounded extremities, median area wide; central area stauros-like; costae transverse, converging at the ends.

Distribution. Anderson's Bay.

90. Pinnularia trevelyana (Donkin) Rab. (Slide 263), (Plate 58, Fig. 37)

  • Rab. 1864, 1, 210.

  • Boyer, 1927, 453.

  • A.S., 1914, 313, 4–6.

  • Navicula trevelyana Donkin, 1864, 1: 210.

Valves linear, with rounded extremities; median area narrow, central area stauros-like; costae divergent in the middle, convergent at the ends.

Distribution. St. Leonards.

– 708 –

91. Pinnularia nodosa (Ehr.) W. Sm., (Slide 165), (Plate 58, Fig. 38)

  • W. Sm. 1856, 96.

  • Boyer, 1916, 108, 30, 19; 1927, 442.

  • Navicula nodosa Ehr., 1854, 17, 2, 12.

Valves triundulate with capitate or rostrate ends; axial area moderate with wide stauros; striae near central nodule radiating, farther out parallel to transapical axis, convergent at ends Length, 50μ.

Distribution. St. Leonards.

Genus Trachyneis Cl., 1894

92. Trachyneis aspera var. pulchella (W. Sm.) Cl. (Slide 61), (see Part IV)

Distribution. Smith's Bay.

93. Trachyneis aspera (Ehr.) Cl. (Slides 4, 60, 255), (see Part II)

Distribution. Anderson's Bay, Portobello.

Genus Neidium Pfitzer, 1871

94. Neidium iridis (Ehr.) Cl. (Slides 154, 248), (see Part II)

Distribution. Bruce's Rocks, Evansdale.

Genus Frustulia Ag., 1824

95. Frustulia weinholdii Hust. (Slide 234), (Plate 58, Fig. 39)

  • Hust. 1936 in A.S. 406, 7, 8; 1937, 730, 1100.

Valves elliptic-lanceolate, ends broadly rounded, central nodule elongate, excentric; striae transverse, slightly radiate near middle; crossed by longitudinal markings. Length, 40–60μ.

Distribution. Evansdale.

96. Frustulia rhomboides var. amphipleuroides Grunow. (Slide 233), (Plate 58, 40), (see Part IV)

Differs from type in elongate central nodule.

Distribution. Evansdale.

Genus Mastogloia Thwaites in W. Sm., 1856, 63

97. Mastogloia smithii Thw. in W. Sm. (Slide 235), (see Part IV)

Distribution. Evansdale.

Genus Amphiprora Ehr., 1843

98. Amphiprora alata var. pulchra (Bail.) CI. (Slide 82), (Plate 58, Fig. 41a, b)

  • CI., 1894, 16.

  • A. pulchra Bail., 1850, 2, 83.

  • Boyer, 1916, pl. 14, f. 3; 1927, 483.d

Frustules panduriform, valves lanceolate, convex, with sinuate keel and junction lines evident; owing to the elevated keel, one side of the frustule is wider than the other; striae of fine moniliform puncta, coarser on the keel.

Distribution. Waitati.

Genus Tropidoneis CI., 1891

99. Tropidoneis lepidoptera (Greg) Cl. (Slides 3,200), (see Part II)

Distribution. Anderon's Bay, Portobello.

Family Cymbellaceae
Genus Amphora Ehr, 1840

100. Amphora proteus Greg. (Slide 42), (see Part II)

Distribution. Smith's Bay.

101. Amphora obtusa Greg. (Slide 192), (see Part IV)

Distribution. Bruce's Rocks.

– 709 –

Genus Epithemia Breb., 1838

102. Epithemia gibberula var. producta Grun. (Slide 227), (Plate 58, Fig. 52)

  • Grun. 1862, 12: 330, pl. 3, f. 9.

  • Boyer 1916, pl. 31, f. 16; 1927, 491

Frustule elliptic-lanceolate; valves arcuate with rostrate extremities; costae distant with intermediate rows of fine moniliform striae.

Distribution. Evansdale.

103. Epithemia zebra var. proboscidea Grun. (Slide 191), (Plate 58, Fig. 43a, b)

  • Grun., 1862, 14.

  • A.S. 1904, 252, 2.

  • Epithemia proboscidea Kütz, 1844, 35, 5, 13.

Frustules rectangular; valves arcuate, with rounded, produced extremities which are at times hooked in or away from the convex margin of the valve; costae distant with intermediate rows of fine moniliform striae. This variety is not truly justified, as the type is variable in outline.

Distribution. Bruce's Rocks.

104. Epithemia muelleri Fricke (Slides 83, 183), (Plate 58, Fig. 44)

  • Fricke in A.S., 1904, 251, 20–24.

Frustule rectangular; valves slightly arcuate, with rounded slightly produced extremities; costae distant, robust, with intermediate rows (2–5) of moniliform striae.

Distribution. Waitati.

Genus Rhopalodia O. Muller, 1895

105. Rhopalodia ventricosa (Kütz.) O. Muller (Slide 186), (see Part II)

Distribution. Bruce's Rocks. Genus Cymbella. Ag., 1830.

106. Cymbella yarrensisA.S. Cl. (Slide 240), (Plate 58, Fig. 45) Cleve, 1894, 162.

Encyonema yarrense A.S.A., 1886, 71, 16.

Valves semi-lanceolate, linear, with acute extremities; median line straight, terminal fissures hooked down, distant from the extremities; median area narrow, central area well defined; striae well defined; ventral margin usually straight.

Distribution. Evansdale.

107. Cymbella ehrenbergi Kütz. (Slide 197), (see Part IV)

Distribution. Bruce's Rocks.

108. Cymbella aspera (Ehr.) Cl. (Slide 81), (see Part II)

Distribution. Waitati.

Genus Gomphonema Ag., 1824.

109. Gomphonema constrictum Ehr. (Slide 239), (see Part IV.)

Distribution. Evansdale.

Genus Gomphoneis Cleve, 1894

110. Gomphoneis herculaneum (Ehr.) Cleve (Slide 74), (Plate 58, Fig. 46)

  • Cl., 1894, (2) 26: 73.

  • Boyer, 1927, 299.

  • Gomphonema herculaneum Ehr. 1854, 35, 7, 12, 13.

Valves broadly clavate, with broadly rounded extremity which at times is slightly constricted beneath; median area narrow; central area more or less rounded with a stigma; costate, costae alternating with rows of fine puncta difficult to see; longitudinal lines difficult to see.

Distribution. Company Bay.

111. Gomphoneis mamilla (Ehr.) Cl. (Slides 79–80, 179), (see Part IV)

Distribution. Waitati.

– 710 –

Family Bacillariaceae
Genus Nitzschia Hassall, 1845, em. Grun. 1880

112. Nitzschia compressa (Bail.) Boyer (Slide 46), (see Part IV)

Distribution. Portobello.

113. Nitzschia acuminata (W. Sm.) Grun. (Slide 225), (Plate 58, Fig. 47)

  • Grun. in Cl. & Grun. 1880, 73.

  • Boyer, 1916, pl. 32, f. 13; 1927, 499.

  • A.S. 1921, 331, 4–5

  • Tryblionella acuminata W. Sm., 1853, 1: 36.

Valves linear, margins usually straight, sometimes slightly constricted in the middle, with acuminate ends. Longitudinal fold smooth or with indistinct striae. Keel puncta not evident.

Distribution. Evansdale.

114. Nitzschia circumsuta (Bail.) Grun. (Slide 138), (Plate 58, Fig. 48)

  • Grun. in Cl. & Grun. 1880, 77

  • Boyer, 1916, 32, 1; 1927, 503.

  • A.S. 1921, 330, 1.

Surirella circumsuta Bail., 1850, 2, 40.

Valves elliptical, with slightly rounded or sub-acute apices; longitudinal fold more or less conspicuous; marginal keel broad and strongly marked, often weakly constricted in the middle; keel punctate, the middle distant, giving the appearance of a pseudonodule; striae transverse or irregular, finely punctate.

Distribution. Bruce's Rocks.

115. Nitzschia granulata Grun. (Slide 85), (Plate 58, Fig. 49)

  • Grun. in Cl. & Grun, 1880, 68.

  • Boyer, 1916, pl. 32, f. 3, 1927, 496.

  • A. S., 1921, 330, 4–9.

  • Tryblionella granulata Grun. in Cl., 1878, 20.

Valves elliptical or elliptic-lanceolate; keel margin furnished with short double rows of three or four small puncta, and rows of large puncta across the valve; longitudinal fold not evident; keel strongly excentric, marginal.

Distribution. Waitati.

116. Nitzschia tryblionella var. yarrensis Grun. (Slide 84), (Plate 58, Fig. 50)

  • Grun. in Cl. & Grun. 1880, 69.

Valve linear-lanceolate, with obtuse cuneiform extremities; at times slightly constricted in the middle; striae transverse with intermediate longitudinal puncta which do not at all times reach the margin; keel puncta definite.

Distribution. Waitati.

117. Nitzschia sigma (Kütz.) W. Sm. (Slide 6), (see Part II)

Distribution. Anderson's Bay.

118. Nitzschia tryblionella Hantzsch (Slide 15), (see Part IV)

Distribution. Anderson's Bay.

119. Nitzschia panduriformis Greg. (Slide 187), (Plate 58, Fig. 51)

  • Greg., 1857, 529, 14, 102.

  • A.S. 331, 19, 21.

  • Boyer, 1927, 497.

Valves elliptical, constricted in the middle, with sub-cuneate to acuminate ends; longitudinal fold distinct, hyaline or punctate; striae transverse and oblique at angle of about 60°. Length, 100–120μ.

Distribution. Bruce's Rocks.

Genus Hantzschia Grun in Cl. and Grun., 1880

120. Hantzschia virgata (Roper) Grun. (Slide 256), (Plate 58, Fig. 52)

  • Grun. in Cl. and Grun. 1880, 104.

  • Boyer, 1916, pl. 32, f. 23; 1927, 528.

  • Nitzschia virgata Roper, 1858, 6: 23.

– 711 –

Valves linear, with rostrate recurved ends; ventral side all but straight, concave on the keel margin; keel puncta prolonged to about one-third the width of the valve, striae transverse.

Distribution. Portobello.

Sub-Order Surirellineae
Family Surirellaceae
Genus Surirella Turpin, 1828

121. Surirella splendida (Ehr.) Kütz (Slides 70, 228), (Plate 58, Fig. 53)

  • Kütz., 1844, 62.

  • A.S., Atl., 1875, 22, 15–17.

  • Navicula splendida Ehr., 1838, 186.

Valves ovate-lanceolate, central area narrow, linear; costae far apart.

Distribution. Smith's Bay, Company's Bay.

122. Surirella filholii Petit (Slide 124), (Plate 58, Fig. 54)

  • Petit, 1877, 30, 5, 18.

Valves panduriform, central area quadrate, costae punctate, large, far apart, central area bordered at irregular intervals by coarse puncta.

Distribution. Bruce's Rocks.

123. Surirella contorta Kitt. (Slides 216, 238), (Plate 59, Fig. 55)

  • Kitt. in A. S., 1875, 56, 2.

Valves ovate, twisted on the longitudinal axis; costae fine, linear, reaching the central area, separated by numerous rows of fine puncta; central area narrow, more or less sigmoid, on opposite ends of the median space a nipple-like process, with a short spine on the apex.

Distribution. St. Clair Beach, Evansdale (Type loc. Auckland).

124. Surirella rattrayi A. S. (Slide 232), (see Part IV)

Distibution. Evansdale.

125. Surirella biseriata Breb. (Slide 241), (Plate 59, Fig. 56)

  • Breb., 1835, 53.

  • Boyer, 1916, pl. 39, f. 12, pl. 35, f. 2; 1927, 535.

  • Navicula bifrons Ehr., 1838, 14.

  • Surirella bifrons Ehr. 1843, 3.

Valves elliptic-lanceolate, obtuse at the ends, costae robust, parallel in the middle, radiate at the ends, reaching the narrow, central space.

Distribution. Evansdale.

126. Surirella gemma (Ehr.) Kütz. (Slides 1, 88), (see Part II)

Distribution. Anderson's Bay.

127. Surirella recedens A. S. (Slides 34, 35), (Plate 59, Fig. 57)

  • A. S., 1875, 19, 2, 3.

  • Boyer, 1927, 38.

Valves ovate; costae broad near margin, suddenly attenuate near linear central space, which is shorter at one end than at the other. Length, 50μ.

Distribution. Smith's Bay.

128. Surirella eximia Grev. (Slides 45, 51), (see Part IV)

Distribution. Evansdale.

129. Surirella striatula Turpin (Slide 246), (see Part IV)

Distribution. Evansdale.

Genus Stenopterobia Hust.

130. Stenopterobia intermedia (Lewis) Hust. (Slides 189, 190), (see Part IV)

Distribution. Portobello.

– 712 –
Genus Podocystis Kütz., 1844

131. Podocystis adriatica Kütz. (Slides 98, 272), (see Part IV)

Distribution. Bruce's Rocks, St. Clair Beach.

Genus Campylodiscus Ehr., 1841

132. Campylodiscus incertus A. S. (Slide 253), (Plate 59, Fig. 58).

A.S., 1875, 15, 14–15.

C. samoensis Grun. in A.S., 1875, 15, 19–20 (described under this name in Part II).

133. Campylodiscus impressus Grun. (Slide 49), (Plate 59, Fig. 59)

  • W.Sm., 1853, 1, 29.

  • A.S. Atl, 1875, 51, 10.

Valves subcircular; costae radiating to about one-third the radius in length; central area traversed by rows of corrugated striae. This does not resemble C. birostratus Deby as suggested by Mills.

Distribution. Portobello.

134. Campylodiscus ralfsii W. Sm. (Slide 29), (Plate 59, Fig. 60)

  • W. Sm., 1853, 1, 30.

  • Boyer, 1927, 551.

  • A.S. Atl., 1875, 14, 1–3.

Valves circular; costae curved in lines radiating from a very narrow median space.

Distribution. Portobello.

135. Campylodiscus taeniatus A.S. (Slide 123), (Plate 59, Fig. 61)

  • A.S., 1875, 51, 1.

Valves more or less circular; costae radiating from the margin, extending inward for one-quarter of the valve, wide on the margin, becoming more slender, then dividing adjacent to the main costae; central area large, transversely punctate to give a cross-hatched effect.

Distribution. Bruce's Rocks.

137. Campylodiscus echeneis Ehr. (Slides 10, 63, 222, 247), (see Part IV)

Distribution. Anderson's Bay, Milford (Temuka), Evansdale.

E.J.F. Wood

, B.A., M.Sc.,
Division of Fisheries and Oceanography,
C.S.I.R.O.,
Cronulla,
Sydney, Australia.

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