Alimentary Canal. The pharynx occupies the first four segments. There is a short, thin-walled proventriculus in v, followed by a long, thick-walled, muscular gizzard in vi. The oesophagus extends from vii to xv and there are no oesophageal glands. The intestine commences in xvi and has no typhlosole.

Vascular System. The dorsal blood vessel is unpaired. There are four pairs of dilated hearts, a pair in each of x, xi, xii and xiii.

Reproductive System. There are two pairs of testes, a pair in x and a pair in xi. Each testis consists of a group of long, tubular processes originating from a point close to the ventral mid-line on the anterior septum of the segment and projecting freely into the coelom of the segment. The ovaries occupy similar positions in xiii, but are smaller and more compact organs. There are two pairs of spermathecae, a pair in viii and a pair in ix. Each spermatheca consists of a long sausage-shaped sac opening by a narrow duct to the exterior. A smaller sausage-shaped diverticulum lies lateral to the spermathecal sac and opens into the spermatheca close to the spermathecal duct (Plate 110, fig. 3). The prostates are long, uncoiled, tubular organs arising in xvii and passing back along the ventro-lateral aspects of the body-wall, terminating in xxiv. A pair of penial chaetae, contained in a fibrous sac, lies close to the lateral aspect of each prostate, extending through xvii and xviii. The penial chaetae have slender shafts, bent fairly sharply in the middle, and have flattened tips terminating in a point (Plate 110, fig. 4). There are three pairs of racemose vesiculae seminales, a pair in each of x, xi and xii, surrounding the lateral and dorsal aspects of the oesophagus.

Paired meganephridial tubules occur in every segment except the first. They are slender and tightly coiled.

Rhododrilus attenuatus n.sp. (Plate 111, figs. 1–4)

Common at depths of 16 to 20 inches in the subsoil of clay soils in the northern regions of North Auckland is a slender unpigmented species of Rhododrilus which the author has named R. attenuatus. The species shows close similarities to R. sutherlandi from Whangarei, but there are certain marked differences in its internal anatomy which serve to distinguish it from that species.

The specimen on which this description is based was collected from Mangonui clay near Mangonui at a depth of 18 inches. It is 79 mm. in length and 2 mm. in diameter and has 145 segments. The prostomium is tanylobous. There is no marked clitellum, but the segments xii to xviii are lightly pigmented. The chaetae commence on ii and are lumbricine in arrangement. On xxiv the arrangement is as follows: ab = cd = 0·75 mm.; aa = 1·25 mm.; bc = 1 mm.; dd = 1·25 mm. Ventral chaetae are absent on xvii, but slender penial chaetae project close to the prostatic pores on that segment.

There are four pairs of spermathecal pores, a pair each at 5/6, 6/7, 7/8 and 8/9 in the line of the chaetal intervals ab. There is a pair of female pores on xiv. Each pore lies anterior to the corresponding chaeta a, on each side. A pair of prostatic pores occurs on xvii; each pore is situated on a small, round, flattened papilla in the line of the chaetal intervals ab. The male pores are not visible externally. The