![Thumbnail: [Volume 79, 1951 page 566]](/journals/rsnz/images/rsnz_79/thumbnails/rsnz_79_03_0808_0566_ac_02.gif)
“Setal arrangement perichaetine. One oesophageal gizzard in one simple segment. Calciferous glands as mere dilations of the oesophagus
![Thumbnail: [Volume 79, 1951 page 567]](/journals/rsnz/images/rsnz_79/thumbnails/rsnz_79_03_0809_0567_ac_02.gif)
in xv and xvi. Purely micronephridial (?). Sexual apparatus purely acanthodriline.” (Stephenson, 1930.)
The genus is confined to New Zealand.
Two species were described by Benham (1902) and referred by him to the genus Plagiochaeta Benham (1892). These two species were subsequently removed from the genus Plagiochaeta to a new genus Hoplochaetina by Michaelsen, since Plagiochaeta is characteristically meganephric, whereas these two species are micronephric. There has been no further record of the genus, and the three species described in this paper bring the total known number of species to five.
The five species may be recognised from the following key:
| a1 One pair of vesiculae seminales | H. robusta n.sp. |
| a2 Two pairs of vesiculae seminales | |
| b1 Spermatheca with one diverticulum | H. pallida n.sp. |
| b2 Spermatheca with small diverticula arranged in a semicircle | H. polyoystis n.sp. |
| a3 Three pairs of vesiculae seminales | |
| c1 Ovaries and testes attached to the anterior septa of their respective segments | H. rossii (Benh.) |
| c2 Ovaries and testes attached to the ventral aspect of the peritoneum in their respective segments | H. ricardi (Benh.) |
The following are descriptions of the three new species H. robusta, H. pallida and H. polycystis. Type specimens in author's collection.
Hoplochaetina robusta n.sp. (Plate 121, figs. 1–3)
A single specimen of this large pink earthworm was collected together with a large number of specimens of the introduced species Allolobophora caliginosa from Waiotira clay loam, under a remnant of native forest among pasture lands two miles south-east along the Mangakahia Valley road from Pakotai, near Whangarei. It is 98 mm. in length, has 166 segments, and a diameter of 7·5 mm. for most of its length.
There is no marked clitellum. The prostomium is epilobous. The chaetae, which commence on ii, are perichaetine in arrangement, and about 48 on each segment, closely spaced around the circumference of the segments, except for a gap of 1·75 mm. between corresponding chaetae a of each segment.
There are two pairs of spermathecal pores, a pair at 7/8 and a pair at 8/9. The pores on each side are in line with the chaeta fourth from the ventral mid-line. A single pair of female pores is present on xiv, each pore situated slightly anterior to the corresponding most medial of the ventral chaetae of that segment. There are two pairs of prostatic pores, a pair on xvii and a pair on xix, each pore situated on a raised white papilla. A longitudinal groove joins the two prostatic pores of each side, traversing xviii, and a male pore lies in each of these grooves, on xviii.
Nephridiopores are not visible. Dorsal pores commence at 19/20, and are present in each intersegmental groove posterior to this.