DESCRIPTIONS OF GENERA AND SPECIES 191 



rudimentary, and doubtless disappear when the sexual organs concerning which 

 there is no information appear. The cells of the funnels are ciliated, a number of 

 cilia to each cell. A peculiar flask-shaped gland opens behind each seta. The 

 oesophagus extends from segments ii-iv. It appears to be a subterranean species. 

 See also FORBES (2). 



Genus PELODRILTTS, BEDDARD. 



DEFINITION. Small, slender worms. Setae paired. Clitellum XI-XIII. Sperm- 

 ducts, two pairs opening on segment XII by four separate orifices. Ovaries 

 in XIII ; oviducts opening on to border line between XII XIII. Spormathecae 

 one pair in VIII. 



This genus consists, at present, of only a single species recently described by myself. 

 Although short and slender in form, and resembling a Lumbriculus, its affinities are 

 clearly with Phreoryctes, from which genus, however, it shows certain important 

 differences. The nephridia of the sexually -mature worm commence as far forward 

 as the seventh segment, and are only absent in the eleventh and twelfth segments ; 

 they are thus present in several of the genital segments. There are two pairs of 

 sperm-ducts, the funnels of which open into the tenth and eleventh segments ; 

 the tubes themselves are much coiled, but open on to the twelfth segment ; they 

 are distinct from each other throughout their whole course, and there are four 

 external pores ; these are situated two on each side of the body, one being in front 

 of the other. The clitellum, contrary to the conditions which obtain in most aquatic 

 Oligochaeta, is undeveloped in the ventral region. The male pores, which lie a little 

 to the anterior of the line of the ventral setae (these setae are absent from the twelfth 

 segment), mark the ventral boundary line of the clitellum. A series of radiating 

 muscular fibres are inserted near the male apertures and probably serve to protrude 

 them during copulation. There is, contrary to what we find in Pkreoryctes, only 

 a single pair of ovaries present, which lie in the thirteenth segment. 



The genus Pelodrilus agrees with Phreoryctes in the following more or less 

 important characters, those marked with an asterisk being the most important. 



(1) Setae sigmoid and paired (Phreoryctes smithii). 



(2) Testes in x, xi. 



*(3) Sperm-ducts two pairs, all four opening separately. 

 *(4) Spermiducal gland absent. 

 (5) Spermathecae anterior to testes. 

 *(6) Hearts long, thin, and much convoluted. 



