140 Illhwls State Laboratory of Natural History. 



rfiale pore is also upon somite XIX, in a longitudinal 

 groove, but is near the anterior margin of that somite. 



Two paiis of prostate glands are present in each 

 species, having their external openings on somites XYIII 

 and XX. The s])ecies also agree in having two ventral 

 crescentic longitudinal grooves (their convexities in- 

 ward), which extend from the middle of somite XVIII 

 to the middle of somite XX, and have modified setae 

 and the external opening of a prostate gland at each of 

 their extremities. In each species somite XIX is with- 

 out ventral setse. 



On the ventral side of alcoholic specimens of D. riparia, 

 an area extending from the middle of somite XYII to 

 the anterior portion of somite XXI and bounded upon 

 the sides by the two longitudinal grooves, is depressed 

 to a depth of about one fifth the diameter of the worm. 

 In alcoholic specimens of D. communis no such depression 

 is noticea^ble. 



Two pairs of spermathecae are present in D. riparia, 

 one pair in each of somites VIII and IX, with the ex- 

 ternal openings at the anterior margins of those somites 

 and in line with the inner rows of setae. D. communis 

 has in addition one pair in somite VII. Although Gar- 

 man makes the possession of three pairs of spermathecae 

 a character of the genus, I feel justified in including the 

 new species in the same genus, especially as other genera 

 of earthworms include species which differ in the number 

 of spermathecae. 



The ovaries and female pores are in the usual position, 

 the former in somite XIII, and the latter upon somite 

 XIV. 



The vascular system of D. riparia is much like that of 

 D. communis., except that in no case has any trace been 

 seen of the double dorsal vessel, which is so constant in 

 the latter species. The presence of a double dorsal vessel 

 is included by Garman among the generic characters of 

 Diplocardia, but I think without sufficient reason, since 

 in other instances species differing in this respect are 

 assigned to one genus. 



