DESCRIPTIONS OF GENERA AND SPECIES 509 



pairs (beginning in the thirteenth segment in one specimen, in the nineteenth segment 

 in another) they are coated with a thick layer of peritoneal cells. 



The spcrmathecae open between vii/viii and viii/ix ; in one individual they both 

 lay in the eighth segment. The duct is quite short, and ensheathed in a thick 

 muscular layer. 



(4) Gordiodrilus ditheca, BEDDARD. 

 G. ditheca, BEDDARD, loc. cit., p. 90. 



Definition. Length, about 40 mm. Clitellum, XIII-XVII. Spermiducal pores on XVIII. 



Spermathecae in VII, without diverticula Hob. Lagos. 



This species only differs from the last in the single pair of spermiducal glands and 

 spermathecae. 



(5) Gordiodrilus dominicensis, BEDDABD. 

 G. dominicensis, BEDDAED, loc. cit., p. 91. 



Definition. Length, 26 mm. ; diameter, 1 1 mm. ; number of segments, 60. Setae of ventral 

 pairs absent upon eighteenth and nineteenth segments. Spermiducal pores on XVIII, XIX. 

 Septa VI/IX specially thickened ; those between V/VI and IX/X tolerably strong. 

 Spermatheca absent. Hal. Dominica, W. Indies. 



The principal distinguishing mark of this ^species is, of course, the absence of 

 the spermathecae. It is, however, just possible that the spermathecae were not yet 

 developed, as the worm had no clitellum. The septal glands extend back as far as 

 the eighth segment. The nephridia commence in the fifth segment ; from the tenth 

 segment onwards the nephridia are invested with a mass of clear peritoneal cells. 



(6) Gordiodrilus zanzibaricus, BEDDAED. 

 G. zanzibaricus, BEDDARD, Q. J. M. S., xxxvi, 1894, p. 252. 



Definition. Length, 25 mm. Clitellum, XIII- -XIX. Ventral setae of segments XVII, 

 XVIII, represented by one seta only. Spermiducal pores upon XVII, XVIII. Septa 

 between segments V/XI thickened, particularly those between VI/IX. Sperm-sac* in XII ; 

 sperm-masses in X, XI. Spermathecae in VIII, IX, with short muscular duct. Hab. 

 Zanzibar. 

 The septal glands of this species are well developed, and extend as far back as the 



seventh segment, there being traces of a pair of these glands in the eighth. 



