♀. Eyes varying from unequivocally hairy to practically bare; brown or green, unbanded, in relaxed specimens. Frons usually of medium width (indices usually 3 to 4, but ranging from 2 to 5), diverging, tomentose; ocellar tubercle not clearly differentiated, but ocelli often represented by one to three small spots or punctures; callus usually small and pale, sometimes relatively large and dark, but always narrower than frons and restricted to its lower half. Subcallus tomentose, with or without hairs. Face and parafacials normal. Antennae of normal tabanine form; third seg-

Fig. 5.—Dasybasis (Protodasyommia) sarpa (Walk.), ♀ ♂: head of ♀; ninth tergite and hypopygium of ♂; eighth sternite and terminal segments of ♀; antenna and palp of ♀ (left). ♂ (right).

ment with the basal four annuli fused and widened to form a “basal plate”, which is sometimes rounded above, or sometimes with a dorsal angle or hump; apical four annuli distinct and forming a clearly differentiated style. Palpi usually slender, somewhat compressed, tapering and rounded at tip. Proboscis short and stout; labella large and soft. Thoracic spiracles widely open, with small lips. Hind tibiae without apical spurs. Wings: basicosta (subepaulet) without setulae; vein sc setulose, at least below; R₄ usually smoothly curved, sometimes more or less angulate and with an incipient appendix; cell R₅ widely open. Genitalia: Terminal segments dorsoventrally compressed; ninth tergite divided into two widely separated triangular plates; caudal ends of spermathecal ducts with characteristic mushroom-shaped expansions (Mackerras, 1955, Fig. 2, I).

♂ Eyes contiguous; upper facets usually small, but somewhat enlarged in one species and markedly so in another. Ocellar tubercle usually clearly visible at vertex, sometimes distinctly raised, and often with more or less clear indications of three ocelli. Palpi short, usually more or less acorn-shaped. Genitalia: Ninth tergite clearly divided in mid-line; style truncate apically in dorsal view.

As at present recognised, the subgenus is restricted to New Zealand, but there is a small group of Australian species which may possibly belong to it.

The species fall into two groups, which I would be inclined to treat as separate subgenera, if the distinguishing characters were more reliable in related, larger subgenera in other countries. They are not completely satisfactory even here, and I believe that the groups had a common origin, so amalgamation or separation does not affect the zoogeographical discussion at the beginning of this paper. They are:

truncata group: Eyes appearing bare or faintly hairy at 15 X; frons of female relatively wide (index usually less than 3); first antennal segment small, not expanded dorsally; basal plate of third rounded or with obtuse dorsal angle (Text-fig. 6, K-M); wings tapering apically, and with relatively narrow cell Cu₂ and anal lobe; vein sc bare or irregularly setulose above (always setulose below in both groups). North and South Islands.

sarpa group: Eyes unequivocally hairy at 15 X; frons of female relatively narrow (index 3 to 5); first antennal segment larger, usually more or less hood-like dorsally;

basal plate of third with sub-basal dorsal angle or hump (Text-fig. 6, N-Q); wings more rounded apically, and with wider cell Cu₂ and anal lobe; vein sc setulose on most of length above. North Island.

If subgeneric distinction is considered desirable, the name Aphopeas End. (syns. Leptotabanus Kröb., Thereviotabanus Kröb,. Neoleptotabanus Miller) is available for the truncata group, and Protodasyommia End. (syns. Therioplectes Kröb. nec Zell., Glaridapha End.) for the sarpa group.

Both groups present problems of speciation similar to those discussed above under Scaptia, although variation within populations appears to be greater, and definition of the species is correspondingly more difficult. I have found no accounts of their behaviour, other than Tillyard's (1926, p. 359), statement that Tabaninae “are found resting on rocks in river-beds; they seldom appear to bite”, and Hudson's (1892) note that D. viridis may be taken in similar situations to the Scaptias. Dr. Miller (personal communication) has confirmed that they are not pests of any note, and he knows of none attacking man. Hudson recorded D. viridis as breeding in moss on tree-trunks in the forest, but his account is unconvincing, and Dr. Miller has informed me that he has observed this species ovipositing in damp sand on the margin of a river.

Note.—Some males with frontal hairs have dark legs and mesopleural hairs, like nigripes, but they are treated here as variants of truncata.

Dasybasis (Protodasyommia) transversa (Walker). Text-fig. 6, A, K.

Tabanus transversus Walker, 1854. Type ♂ ♀, from New Zealand, in the British Museum (Natural History).

Leptotabanus transversus (Walker). Kröber, 1931, p. 76.

Neoleptotabanus transversus (Walker). Miller, 1945, p. 72; 1950, p. 69.

Material Examined: 4 ♂ ♂, 5 ♀ ♀, including specimens returned by Mr. Oldroyd as agreeing with the types.

A small, easily recognised, brown to greyish brown species, with unusually large stigma, characteristic pattern of brown spots on the wing, and median pale stripe or row of triangles on abdominal tergites. Length, 9–10 mm.

♀. Head: Eyes (relaxed) brown; bare. Frons slightly diverging, index 2.5 to 3, fawn-cream, irregularly suffused with brown, and with brown hairs; vertexal triangle inconspicuous; position of anterior ocellus indicated by a small brown spot; callus small, pale brown, about one-third width of frons at base, more or less triangular, and with a short median extension Subcallus, parafacials and face greyish to yellowish cream; subcallus sometimes with a few fine cream hairs, parafacials and face with cream and some brown hairs. Antennae: First and second segments light yellowish fawn, with some greyish overlay, and with brown to black hairs; basal

Fig. 6.—Dasybasis: A-E and K-M, truncata group; F-J and N-R, sarpa group. A-J, frons of ♀ of: A, transversa (Walk.); B, C, the two possible females of thereviformis, n. nov.; D, truncata (Walk.); E, nigripes (Kröb.); F, sarpa (Walk.); G, loewi End.; H, viridis (Huds.); I, opla (Walk.); J, bratrankii (Now.). K-N, antenna of ♀ (except L, which is of ♂):, palp of ♀ and palp of ♂ of: K, transversa; L, thereviformis; M, truncata; N, loewi. O-R, antenna and palp of ♀ of: O, viridis; P, opla; Q, bratrankii; R, sp. A nr. bratrankii.

plate of third bright yellowish brown, style brown. Palpi fawn-cream, with relatively long cream and brown hairs. Beard cream.

Thorax: Scutum with ground colour considerably reduced, the appearance being of a grey to greyish fawn scutum, bearing a pair of broad admedian brown stripes, fading behind suture, a pair of broad sublateral brown stripes, interrupted by suture, and a brown patch above wing root. Hairs erect dark brown, and appressed dull cream; marginal hairs predominantly brown. Scutellum grey, paler apically and laterally, with brown and dull cream hairs. Pleurae pale fawn-grey, with cream hairs.

Legs: Light brown, darkening a little on tarsi, especially on the fore pair; hairs predominantly cream to yellowish cream on femora and tibiae, predominantly brown on apical parts of tibiae and all tarsi; hind tibial fringes poorly developed, predominantly brown.

Wings: Longer than usual, projecting well beyond tip of abdomen; lightly suffused with brown; stigma large, brown. There are distinct brown clouds across apices of basal cells, apex of discal cell, and at fork of R₄₊₅. In some specimens the centres of the cells are a little paler than the general ground colour.

Abdomen: Brown; median area and lateral margin of first tergite pale grey; second and subsequent tergites with a variable median pale grey stripe, sometimes reduced to a row of median triangles, and with narrow pale grey apical margins, which widen to form apical lateral triangles. Hairs brown on the darker parts, cream on the paler areas. Venter creamy fawn, with paler apical margins to the sternites, and pale cream hairs.

♂ Similar to female in coloration and markings. Upper facets of eyes markedly enlarged, reddish brown, contrasting with the darker, small, lower and lateral facets; ocellar tubercle small, deeply sunken. Palpi short and relatively broad, yellow, with long cream and some brown hairs.

Distribution. North Island: Kaitaia; Taranga Is. (Kröber, 1931); Auckland; Tangoio Falls, December; Ohakune, February, March, April; Lake Horowhenua, February (Kröber, 1931); Mangatiriri R., Tararua Range; Wellington, February.

D. transversa is the only species in New Zealand which looks superficially as if it might have been derived from northern Cydistomyia stock. However, it has so many features in common with the other members of the truncata group, particularly with D. thereviformis, that its relationship to them can scarcely be doubted.

Dasybasis (Protodasyommia) thereviformis, nom. nov. Text-fig. 6, B, C, L.

Thereviotabanus viridis Kröber, 1931, p. 78; Miller, 1950, p. 70; nec Comptosia virida Hudson, 1892 (q.v.). Type ♂, from New Zealand, in the British Museum (Natural History).

Material Examined: 18 ♂ ♂, 2 ♀ ♀, including a male returned by Mr. Oldroyd as agreeing with the type in the British Museum.

A grey, almost concolorous species, with short but distinct hairs on the eyes, deeply buried ocellar tubercle in the male, brown legs, and predominantly pale hairs on the abdominal tergites. The male will be described first, as there is some doubt about the associated females. Length: ♂, 10–12 mm; ♀, 11, 13 mm.

♂ Head: Eyes green when relaxed; with short, fine, pale hairs, which are visible at 15 X; upper facets not enlarged. Ocellar tubercle small and sunken, difficult to see. No long frontal hairs between eyes. Frontal triangle and subcallus creamy grey, with only an occasional pale hair. Parafacials and face creamy grey, with mixed dark brown and greyish cream hairs laterally, entirely greyish cream medially. Antennae: Basal segments brown, with a grey overlay and black hairs; third dark brown, paler at base, basal plate often with a more definite dorsal angle than in other members of the group. Palpi light greyish fawn, with long yellowish cream and a few dark hairs. Beard greyish to yellowish cream.

Thorax: Scutum almost uniformly olive-grey, paler anteriorly and laterally, but with only faint indications of paler vittae. Hairs erect dark brown and long semiappressed dull cream; marginal hairs predominantly brown in front of wing root, cream above and behind it. Scutellum grey, with some dark hairs on disc and cream fringe. Pleurae pale grey, with greyish white to cream hairs.

Legs: Light brown; femora darkened basally, with a greyish overlay in some specimens; fore tarsi also somewhat darker. Hairs creamy white to cream on femora and tibiae, more predominantly brown apically on fore tibiae and on all tarsi; hind tibial fringes mixed cream and brown.

Wings: Faintly greyish, costal cell barely, if at all, darkened; stigma brown, inconspicuous; veins light brown.

Abdomen: Grey, with the apical edges of the tergites narrowly pale, and with mixed long fine cream and dark brown hairs, the former predominating, especially on apical and lateral edges of tergites. Venter grey, with narrow apical pale margins to the sternites, and long fine creamy white hairs.

♀. The females are both similar to the males, but more definitely grey in general colour, and with a fairly evident median paler triangle on the second abdominal tergite. Hairs on eyes very fine, but visible at 15 ×. Antennae missing. One (Wellington, N.I., Hudson, in the Canterbury Museum) is relatively longbodied (length 13 mm), and has a wide (index 1.8), diverging frons, with a well developed brown callus (Text-fig. 6, B); its palpi (Text-fig. 6, L) are short, and covered with long cream hairs. The other (Waiho, S.I., 26.1.1922, Tonnoir, in the Canterbury Museum) is shorter (length 11 mm), more thick-set, and has a narrower (index 3), nearly parallel frons, with a very small, inconspicuous callus, which is almost entirely covered by tomentum (Text-fig. 6, C); hairs on palpi predominantly dark brown.

In the absence of more material, it is impossible to say what may be the relationship between these females. I cannot separate the males into two series, which might correspond with them.

Distribution. North Island: Tiritea R., January; Wellington, January, March. South Island: White Rock, Canterbury, December; Waiho, January; Alexandra (Kröber, 1931).

It seems likely that two species may be recognizable in life by having bright green eyes, thereviformis, which is grey in general colour, and viridis, which is more olive and has different antennae (Text-fig. 6, 0). Hudson apparently saw both, although his type series included only the latter.

Dasybasis (Protodasyommia) truncata (Walker). Text-fig. 6, D, M.

Tabanus truncatus Walker, 1850. Type ♀, from New Zealand, in the British Museum (Natural History).

Mesomyia maoriorum Bigot, 1892. Type ♂, from New Zealand, in the British Museum (Natural History). Synonymy by Ricardo, 1915, who noted the presence of black hairs on the subcallus and between the eyes.

Aphopeas priscum Enderlein, 1930. Type ♀, from New Zealand, in the Zoological Museum, Berlin. Synonymy by Krober, 1931, on authority of F. W. Edwards.

Aphopeas truncatus (Walker). Krober, 1931, p. 72; Miller, 1950, p. 69.

Material Examined: 10 ♂ ♂, 9 ♀ ♀, including specimens returned by Mr. Oldroyd as agreeing with the type.

A small, dark, brown or grey to blackish species, with wide frons, brown legs, and variable pale markings on abdominal tergites; male with long frontal hairs Length, 8–10 mm.

♀. Head: Eyes dark brown (relaxed); bare. Frons diverging, index 1.8 to 2.2, light grey, often irregularly patterned with brown, and with relatively long and dense dark brown hairs; vertexal triangle indefinite; ocellar tubercle sometimes indicated by a brownish mark, but ocellar spots usually absent; callus dark brown, raised in lateral view, about one-third width of frons, irregularly triangular or diamond-shaped, and with a short median extension. Subcallus projecting, pale to creamy grey, with numerous brown and yellowish cream hairs. Parafacials and face pale to creamy grey, with yellowish cream and brown hairs. Antennae: First and second segments light brown, the first with some greyish overlay, both with brown to black hairs; third dark brown, paler at base. Palpi variable in length and thickness, light greyish to brownish fawn, with relatively long cream and brown hairs. Beard greyish cream.

Thorax: Scutum and scutellum brown, sometimes dark, with greyish overlay in sublateral areas anteriorly and laterally in front of wing root, and with more or less well developed pale dorsocentral vittae. Hairs erect black and appressed dull yellowish cream; marginal hairs predominantly brown in front of wing root, mixed brown and dull cream behind it and on scutellum. Pleurae grey, variably marked with brown, and with entirely cream to yellowish cream hairs.

Legs: Brown, the mid and hind tibiae yellowish; hairs mainly yellowish cream on basal segments, brown apically on tibae and on all tarsi.

Wings: Lightly suffused with greyish brown; stigma dark brown; veins brown.

Abdomen: Dark to blackish brown, with a well developed median pale grey triangle and apical margin on the second tergite, and variable, usually less conspicuous, triangles and pale margins on the remainder. Hairs dark brown to black on most of the abdomen, yellowish cream on the pale triangles, irregularly on the apical margins, and more definitely on the apical lateral corners of the tergites. Venter grey, the sternites with irregular basal brown bands; hairs yellowish cream, most conspicuous on the apical edges of the sternites, and more or less mixed with dark brown in the median zone.

♂ Generally darker than female. Upper facets of eyes not enlarged; ocellar tubercle prominent, reaching level of eyes. There is a row of strong black hairs projecting between the eyes on the full length of the frons, which is characteristic