and the doubtful species O. levis (Hutton, 1876). To these must now be added the three new species O. sylvestris, O. tricystis and O. brucei, described in this paper.

O. levis was described by Hutton as Lumbricus levis and the type specimen was re-examined by Benham (1898) and placed in the genus Octochaetus. When re-examined by Benham the type was in a poor state of preservation and could only be identified as “a species of Octochaetus.”

O. multiporus and O. thomasi are very similar species, their principal point of difference being that O. multiporus is a very large species while O. thomasi is rather small.

A species described by Beddard (1890) under the name of Acanthodrilus antarcticus must be mentioned here. This species was included by Ude (1905) in the genus Octochaetus as O. antarcticus. Since Beddard's original description makes no mention of the form of nephridia found in this species and the only difference between Octochaetus and Acanthodrilus (or, for that matter, Maoridrilus) is in the form of the nephridia, it must remain as a “species incertae sedis.”

The New Zealand species of Octochaetus (except O. levis) may be identified from the following key:

The following are descriptions of the three new species O. tricystis, O. sylvestris and O. brucei. Type specimens in the author's collection.

Octochaetus tricystis n.sp. (Plate 115, figs. 1–3)

Several specimens of this new species were collected from Kiwitea loam in the R. C. Bruce Park, an area of virgin bush (matai, rimu, tawa and ngaio) situated a few miles south of Hunterville. The body is unpigmented except for the clitellum, which is purplish in colour and extends over the dorsal and lateral surfaces of xiv–xvii and the posterior portion of xiii. The specimen described below is 82 mm. long, 5 mm. in diameter, and has 94 segments.

The prostomium is prolobous. There are eight chaetae on each segment, arranged in pairs. On xxiv the arrangement of the chaetae is as follows:

ab = 1 mm.; cd = 1·5 mm.; aa = 2·5 mm.; bc = 2 mm.; dd = 5 mm.

There are two pairs of spermathecal pores, a pair at 7/8, and a pair at 8/9, in line with chaeta b. A pair of female pores occurs on xiv, a pore slightly anterior and medial to chaeta a on each side. There are two pairs of prostatic pores, a pair on xvii and a pair on xix, situated on rounded white papillae lateral to chaeta b. It is unusual for chaeta b to be present on the segments bearing the prostatic papillae, but in this species they do occur. A narrow groove, passing