new Earthicorms in the British Museum. 283 



Michaelsen and I failed to find any diverticulum. Our 

 specimens were not fully mature, but on the hypothesis of 

 an identity between these two species it seems highly im- 

 probable that even in a series of sections no traces could be 

 found of an organ which in the adult reaches so great a deve- 

 lopment. Moreover, in the descriptions of P. insularis no 

 mention is made of a ventral sucker. 



Another allied species is undoubtedly P. matsushimensis, 

 for a clear description of which we are indebted to Akira 

 Jizuka *. However, this Japanese Poatodrilus seems to be 

 really different from our species. 



First it is a larger species than ours, as its length ranges 

 from 90 to 110 millim., with a diameter of 3-3*5 millim., 

 while our specimens, with a diameter loo of 3 millim., have 

 only a length of 43-47 millim. Besides it may be noted 

 that the clitellum of P. matsushimensis is described as being 

 well developed all round the body (and the same is shown 

 by the figures), whilst in our species the clitellum is dis- 

 tinctly saddle-shaped. Finally the appearance of the prostate 

 is (so far as one can judge from the figures) somewhat 

 different. 



Perichceta brevis, sp. n. (PI. IX. figs. 6, 7.) 



Uab. Christmas Island (east coast). Coll. by C. W. 

 Andrews, Esq. 



A very small species measuring only 15-20 millim. in 

 length by a diameter of 2-2'5 millim.; it consists of about 

 70-80 segments ; the colour (in spirit) is a deep yellow. 



The setas on segment 25 are approximately 50. 



The clitellum occupies somites 14, 15, 16. 



The male pores are on high conical and almost lateral 

 porophores, which are partially visible from behind. The 

 boundaries of these porophores are laterally indistinct; in 

 front and behind they are marked by the intersegmental 

 furrows 17-18 and 18-19, which are here deflected. 14 setse 

 are visible between the male pores. 



The oviducal pore is single and lies in a whitish spot on 

 the 14th segment. 



There are three pairs of spermathecal pores between somites 

 5-6, 6-7 ; and 7-8, close to the lateral line. 



I have not been able to determine the position of the first 

 dorsal pore. There are no copulatory papilkc. 



None of the septa are noticeably thick and none arc wanting. 



The gizzard is between conical and tun-shaped ; it is as 



* Aimotationes Zoological Japonenses, vol. ii. pars i. (Tokyo, 1898). 



