1886,] LITTLE-KNOWN EARTHWORMS. 301 



there are three or four pairs of genital papillae, one to each of a 

 correspoudiiig 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 l/th 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 setae are continuous all round the boily 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 spermathecse are separated from each other 

 by very stout mesenteries, which are also found between segments 8- 

 7, 7-0, C-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 spermatliecse ; 

 it does not, as is so commonly the case (e. g. in P. ajjlnis) occupy two 

 segments, the intermediate mesentery having disappeared. The 

 spermathecse consist of an oval or sometimes cylindrical pouch 

 communicating with the exterior by a narrow duct, to which is 

 attached a short diverticulum of nmch the same shape as tlie pouch. 

 The diverticulum appears never to lie in a dift'erent 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 oesophagus widens into the intestine at about the 20th segment ; 



' The extension of the clitellum over four segments, combined with the 

 regularity and uniform size of the seta3, makes it difficult, in the absence of 

 additional information, to distiugnish this species from P. ccsrulcu, E. P.; it is 

 stated, however, that in P. cceriilea the female generative orifices are jjaired. 

 Nevertheless this latter difference is not pei-haps of very fundamental value ; it 

 must at any rate be discounted by my own observations vvitli regard to Meffasook'X 

 (Ann. & Blag. Nat. Hist., Oct. 1883), where the female pore is sometimes single and 

 sometimes double. Ferichceki taifensis of Grube (Reise der Novara, Anneliden, 

 p. 3t>, pi. iv. fig. 3) is a very doubtful species, agreeing witli P. horsti in having 

 only two pairs of spermatliecos situated in the 8tli 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. 553) ai-e 

 in need of revision. Lionhricus kcrguclarum appears to me from his description 

 to be imdoubtedly referable to the getuis Acanthodrilus, and perhaps to Lan- 

 kester's species A. kcrguelcncnsis; L. tongaciisis is certainly not a Lumbricus, 

 and perhaps belongs to the same genus as the last. 



