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Volume 79, 1951
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Internal Anatomy (Plate 108, fig. 2)

The septa vi/vii, vii/viii, viii/ix, ix/x, x/xi, xi/xii and xii/xiii are muscular and thickened.

Alimentary Canal. A small globular pharynx occupies the first four segments. There is a short, thin-walled proventriculus in v and a thick-walled muscular gizzard in vi. The oesophagus extends from vii to xv. There are no oesophageal glands. The intestine commences in xvi. It is thin-walled and the typhlosole is not strongly developed.

Vascular System. The dorsal blood vessel is unpaired. Four pairs of dilated hearts originate from the dorsal vessel in × to xiii. The hearts of xiii are smaller in diameter than those of × to xii.

Reproductive System. There are two pairs of testes, a pair in x and a pair in xi. Each testis takes the form of a cluster of thread-like processes attached to the anterior septum of its segment close to the median ventral line. A pair of ovaries is situated in xiii. The ovaries are similar in form to the testes. There are two pairs of spermathecae, a pair in viii and a pair in ix. Each is in the form of an ovoidal sac with an anterior digitate diverticulum, and opens to the exterior at the extreme anterior margin of its segment in line with the chaetal interval ab. (Plate 108, fig. 3.)

A pair of tubular prostates is present. Each arises from a narrow duct in xvii and follows a convoluted course through xviii, xix, and xx into xxi, where it terminates. A transparent sac containing penial

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Fig. 1—Rhododrilus albidus. Ventral aspect, segments i–xxii.
Fig. 2—R. albidus. Dissection from the dorsal aspect.
Fig. 3—R. albidus. Left spermatheca, lateral aspect.

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Fig. 1—R. intermedius. Ventral aspect, segments i–xxi.
Fig. 2—R. intermedius. Dissection from the dorsal aspect.
Fig. 3—R. intermedius. Right spermatheca, anterior aspect.
Fig. 4—R. intermedius. a, Penial chaeta. b, Tip of penial chaeta.

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Fig. 1—R. disparatus. Ventral aspect, segments i–xxii.
Fig. 2—R. disparatus. Dissection from the dorsal aspect.
Fig. 3—R. disparatus. Left apermatheca, lateral aspect.

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Fig. 1—R. sutherlandi. Ventral aspect, segments i–xx.
Fig. 2—R. sutherlandi. Dissection from the dorsal aspect.
Fig. 3—R. sutherlandi. Left posterior spermatheca, lateral aspect.
Fig. 4—R. sutherlandi. Penial chaeta.

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Fig. 1—R. papaensis. Ventral aspect, segments i–xix.
Fig. 2—R. papaensis. Dissection from the dorsal aspect.
Fig. 3—R. papaensis. Left posterior spermatheca, medial aspect.
Fig. 4—R. papaensis. Penial chaeta.

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Fig. 1—R. macroseptus. Ventral aspect, segments i–xxii.
Fig. 2—R. macroseptus. Dissection from the dorsal aspect.
Fig. 3—R. macroseptus. Right posterior spermatheca, anterior aspect.
Fig. 4—R. macroseptus. Penial chaeta.

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Fig. 1—R. benhami. Ventral aspect, segments i–xxii.
Fig. 2—R. benhami. Dissection from the dorsal aspect.
Fig. 3—R. benhami. Right posterior spermatheca, anterior aspect.
Fig. 4—R. benhami. Penial chaeta.

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Fig. 1—R. attenuatus. Ventral aspect, segments i–xviii.
Fig. 2—R. attenuatus. Dissection from the dorsal aspect.
Fig. 3—R. attenuatus. Right posterior spermatheca, lateral aspect.
Fig. 4—R. attenuatus. Penial chaeta.

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Fig. 1—R. minimus. Ventral aspect, segments i–xviii.
Fig. 2—R. minimus. Dissection from the dorsal aspect.
Fig. 3—R. minimus. Right posterior spermatheca, anterior aspect.
Fig. 4—R. minimus. Penial chaeta.

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Fig. 1—R. aduncocystis. Ventral aspect, segments i–xxi.
Fig. 2—R. aduncocystis. Dissection from the dorsal aspect.
Fig. 3—R. aduncocystis. Right posterior spermatheca. posterior aspect.
Fig. 4—R. aduncocystis. a. Penial chaeta, b, Tip of penial chaeta.

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Fig. 1—R. robustus. Ventral aspect, segments i–xx.
Fig. 2—R. robustus. Dissection from the dorsal aspect.
Fig. 3—R. robustus. Left spermatheca of vii, anterior aspect.
at. = spermathecal atrium: e.g. cerebral ganglion; ch. = chaeta; d.b.v. = dorsal blood vessel; d.div. = duct of spermathecal diverticulum; div. = spermathecal diverticulum; f.p. = female pore; g. = gizzard; h. = heart; int. = intestine; m. = month; mn. = micronephridial tubule; m.p. = male pore; n. meganephridial tubule; o. = ovary; od. = oviduct; oe. = oesophagus; oe.gl. = oesophageal gland; o.f. = ovarian funnel; p. = prostate; pap. = papilla; p.ch. = penial chaeta; p.d. = prostatic duct; peri. = peristomium; ph. = phyrnx; p.p. = prostatic pore; pr. = prostomium; pv. = proventriculus; s. = septum; sac = sac = containing the penial chaetae; sal.gl. = salivary gland; s.l.v. = supra-intestinal vessel; sp. = spermathecal sac; sp.d. = spermathecal duct; sp.p. = spermathecal pore; t. = testis; t.f. = testicular funnel; t.pub. = tuberculum pubertatis; v.s. = vesicula seminalis.

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chaetae lies close to each prostatic duct in xvii. Each penial chaeta has an elongate gently curved shaft and is very sharply recurved distally (Plate 108, fig. 4). There are two pairs of botryoidal vesiculae seminales, a pair in xi and a pair in xii.

Paired meganephridia are present in every segment except the first.

Rhododrilus macroseptus n.sp. (Plate 109, figs. 1–4)

This is a large earthworm species, fairly common in virgin soils in the hills near the western sea coast of the Waikato, around Raglan and Kawhia. It is light pink when living, colourless when killed in alcohol. The specimen described below was collected from a small remnant of native forest near the crest of the main ridge of the Raglan Range about a mile south of the highest point on the Hamilton-Raglan road. It is 386 mm. in length and 11 mm. in diameter behind the clitellum, and has 236 segments. All the segments have secondary annulations, the number of annuli in each segment varying from two to seven. The prostomium is prolobous. There are eight chaetae on each segment, arranged in four pairs. On xxiv the arrangement is as follows:

ab = 2 mm.; cd = 3 mm.; aa = 5 mm.; bc = 6 mm.; dd = 10·5 mm. The clitellum completely surrounds segments xiv–xvii and extends over the posterior portion of xiii and the anterior portion of xviii. There are two pairs of spermathecal pores, a pair at 7/8 and a pair at 8/9, in line with chaeta b on each side. The female pores are situated on xiv [ unclear: ] , one on each side, anterior and slightly lateral to chaeta a. The prostatic pores are situated on top of a pair of prominent conical papillae, one on each side of xvii in the position of the pair of chaetae ab. A penial chaeta can be seen projecting from the apex of one of the prostatic papillae.

The tubercula pubertatis take the form of a pair of small white pads, one on each side of the ventral mid-line close to the hinder margins of segments x, xi, xiv, xv, xix and xx. A smaller unpaired tuberculum occurs on the left hand side of xxi, close to the hinder margin and to the ventral mid-line.

Nephridiopores commence on ii and occur in a single series on each side in line with chaeta c.

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