1886. ] LITTLE-KNOWN EARTA WORMS. 301 
there are three or four pairs of genital papillee, one to each of a 
corresponding number of segments following the 18th. There was, 
however, no indication of an additional median papilla on each of 
the segments as in P. horsti, nor does Perrier mention anything of 
the kind. 
The clitellum is not, as is so generally the case, restricted to three 
segments ; but, at least in one specimen, extended from segment 14 to 
17 inclusive; on the 17th segment, however, it was only developed 
on the dorsal region of the body, 
The orifice of the oviducts occupies the usual position on the 
ventral median line of the 14th segment’. The spermathecal 
orifices are between the 7th and 8th and Sth and 9th segments. 
The sete are continuous all round the body and are everywhere 
of uniform size. 
With regard to internal structure, there are one or two features in 
which this species is peculiar. 
In the first place, the spermathecee are separated from each other 
by very stout mesenteries, which are also found between segments 8— 
7, 7-6, 6-5; in front of the fifth segment the mesenteries are more 
or less indistinguishable, forming a mass of muscles which bind the 
pharynx to the parietes ; behind the 9th segment the mesenteries 
are comparatively thin and delicate. The gizzard is situated in the 
Sth segment, that which contains the anterior pair of spermathece ; 
it does not, as isso commonly the case (e. g. in P. affinis) occupy two 
segments, the intermediate mesentery having disappeared. The 
spermathecz consist of an oval or sometimes cylindrical pouch 
communicating with the exterior by a narrow duct, to which is 
attached a short diverticulum of much the same shape as the pouch. 
The diverticulum appears never to lie in a different segment from the 
spermatheca. 
The ovaries and oviducts were very distinct, and appear to occupy 
the normal position. 
The vasa deferentia open on to the exterior in common with the 
duct of a compact prostate. 
The testes are to the number of two pairs and in the usual position. 
The cesophagus widens into the intestine at about the 20th segment ; 
1 The extension of the clitellum over four segments, combined with the 
regularity and uniform size of the setee, makes it difficult, in the absence of 
additional information, to distinguish this species from P. ceru/ea, BE. P.; it is 
stated, however, that in P. cerulea the female generative orifices are paired. 
Nevertheless this latter difference is not perhaps of very fundamental value; it 
must at any rate be discounted by my own observations with regard to Megascolex 
(Ann. & Mag. Nat. Hist., Oct. 1883), where the female pore issometimes single and 
sometimes double. Pericheta taitensis of Grube (Reise der Novara, Anneliden, 
p. 36, pl. iv. fig. 2) is a very doubtful species, agreeing with P. horsti in having 
only two pairs of spermathec situated in the 8th and 9th segments. It may 
possibly be identical with it. I may take this opportunity of remarking that 
several other species described by Grube (MB. Akad. Berlin, 1877, p. 558) are 
in need of revision. Lumbricus kerguelarum appears to me from his description 
to be undoubtedly referable to the genus Acanthodrilus, and perhaps to Lan- 
kester’s species 4. kerguelenensis; L. tongaensis is certainly not a Lumbricus, 
and perhaps belongs to the same genus as the last. 
