NEW ENGLISH GENUS OP AQUATIC OLIGOOHJITA. 173 



the peripheral or tegumentary vessels in each of the posterior 

 somites. 



I may note a peculiar appearance occurring in the larger 

 blood-vessels ; the blood-clot has not a smooth surface, but a 

 fringe of needle-like processes set at right angles to general sur- 

 face of clot, and recalling a crystalline structure (see fig. 18). 



III. The Affinities of Sparganophilus. 



From the character and extent of the clitellum the genus 

 evidently belongs either to the family Geoscolicidae or to 

 the Ehinodrilidse.i The possession of tubercul a puber- 

 tatis points more directly to the latter, for except in the 

 family Lumbricidse these organs are known only in 

 Rhinodrilus, Hormogaster, and Microchgeta.^ Anteus 

 probably is another instance, for both Horst^ and Perrier* 

 describe a band extending along each side of the ventral surface 

 ofa certain portion of the clitellum. Urobenus, too, will very 

 probably be found to possess these structures, though my 

 specimens were too badly preserved for me to be certain of 

 their existence. 



The situation of the generative pore at the hinder margin 

 of Somite XVIII separates the worm from the Lumbricidae, 

 whilst it marks a point of agreement with the genera Rhino- 

 drilus and Hormogaster so far as concerns the interseg- 

 mental position of the pore. 



The arrangement of the sperm-sacs and their number refer 

 Sparganophilus to the Rhinodrilidae, and several other 

 characters of the family are presented by it. 



In one point, however, it dififers from the members of 

 this family, viz. in the absence of oesophageal or intestinal 

 diverticula. 



Sparganophilus tamesis, then, is one of the Rhino- 



^ For references to descriptions of the genera here named, see my 

 "Attempt to Classify Eartliworms," ' Quart. Journ. Micr. Sci.,' vol. xxxi. 



2 Benham, ' Proc. Zool. Soc.,' 1892. 



3 ' Notes from tlie Leydeu Museum,' xiii, p. 77. 

 ■• Perrier, ' Nouv. Arch. d. Museum,' 1872. 



