BY E. J. GODDARD. 863 



directed towards the dorsal region of the body, and the outer 

 limb longer than the inner and passing down on the inner side of 

 the lateral vessel to join the bladder. The winding of the canal 

 is very similar to that of Orobdella and Herpobdella. The figure 

 of the nephridium, as reconstructed by Graf from sections of 

 Herpobdella octoculata (Linne) 1758, ( = Nephelis vulgaris Moq.- 

 Tandon, 1827) is, as Oka has mentioned in his description of 

 Orobdella, false inasmuch as he has represented the canal as 

 running a simple course from the capsule to the bladder. As in 

 Orobdella and Herpobdella, so in this new genus, the canal-region 

 of the nephridium consists of a number of large granular cells 

 placed in alignment to form a row. The row of cells is turned on 

 itself several times, so that in transverse section the canal, which 

 pierces the cells in a direction parallel to the length of the row, 

 is seen three or more times. In places, owing to the apparent 

 fusion of the cells and the impossibility of differentiating between 

 the limits of the constituent cells, one might readily imagine that 

 there was a single, simple row of cells, in which was present a 

 much winding canal. That such is not the case is plainly shown 

 in certain regions of the structure by the distinct elementary 

 nature of the constituent cells, each permeated by a single canal 

 when one differentiates between a transverse and a longitudinal 

 section of such a cell. 



The bladders attached to the distal extremity of the nephridial 

 canal have the form of a flask, with a very wide venter, continued 

 into a very narrow attenuated neck, which opens on the lateral 

 ventral region of the body through the nephridiopore. 



Remarks. — Undoubtedly the Hirudinea in general represent a 

 group of an archaic nature. Their distribution would suggest a 

 great antiquity for the class, and this is supported anatomically 

 by the wide differences, in regard to various organs, in members 

 closely allied from the point of view of classification. 



Regarding the relationship of the Rhynchobdellidce and 

 Arhynchobdellidce, one is forced to conclude that these two groups 

 have been evolved from an old stock, probably closely allied to 

 the Oligocha^ta, sufficiently long enough to allow of the develop- 



