neio Genus of Oligochinta. 93 



Running along the dorsal side of the oesophagus the supra- 

 intestinal vessel first becomes evident in this region of the 

 body. Gordiodrilus dominicensis has the two hearts of seg- 

 ments X. and xi. that are found in other species. 



There are three specially thickened septa which separate 

 segments vi./vii., vii./viii., and viii./ix. The septa lying 

 between v./vi. and ix./x. are also tolerably strong. 



The nephridia are paired ; they commence in the vth 

 segment, and are present in tiie genital segments. From the 

 tenth segment onwards they are invested, as in the other 

 species of the genus, with a mass of clear peritoneal cells. 

 The funnels opening into the segment in front of that which 

 bears the external aperture were seen. / could find no blood- 

 vessels npon the nephridia either in sections or in teased 

 glycerine preparations of the organs. This statement applies 

 to the other species also. 



The reproductive system appears to differ from that of all 

 other species of the genus in the total absence of spermato- 

 thecEe. We are at the present time acquainted with several 

 Oligochseta which have no spermatothecaj ; for the most part 

 these belong to genera where the spermatothecai are normally 

 present. There is therefore nothing extraordinary in their 

 absence from Gordiodrilus dominicensis^ though present in 

 the other species of the genus. The testes are in segments 

 X. and xi. In one out of the two or three individuals 

 examined by me there were two pairs of ovaries, though but 

 a single pair of oviducts occupying the usual position. 



In other particulars the reproductive organs are quite like 

 those of Gordiodrilus elegans. 



It will be clear from the foregoing description that this 

 species differs but slightly from G. elegans. The only well- 

 marked point of difference is the absence of spermatothecce. 

 If I have not by some accident overlooked these structures 

 their absence is of course sufficient to separate the two species. 



III. Diagnoses of the Genus and Species. 



From the above anatomical description of the five species 

 of the genus I attempt the following diagnoses : — 



Genus GORDIODRILUS, gen. nov. 



Small slender terrestrial Oligochceta^ loith 'paired setoi of the 

 usual Lumbricid pattern. Clitellum variable^ always inclu- 



