1 78 CALIFORNIA ACADEMY OF SCIEMCES. [Proc. 3D Ser. 



Affinity. — Diplocardia Afichaeheni resQxnhles, D. Udei 2ind 

 D. Eiseni in possessing spermathecal sexual setse accom- 

 panied by interior glandular structures in the body-wall. It 

 differs from all other species so far described in the position 

 of the spermathecal pores, which in somite IX are pre- 

 septal, while in somite VIII they are postseptal. As far as 

 we know it also differs in the possession of a glandular crop 

 in two of the clitellar somites similar to the one described 

 in Pontodrilits Michaelseni (Eisen, 17). 



External Characters. 



Body. — The body is cylindrical, and does not taper either 

 to head or end. The somites are not well marked off. 

 The width is about the same at any point of the body, ex- 

 cept at the clitellum, which widens a very little. 



Somites. — The three anterior somites are much narrower 

 than the others, and of about equal width, being about three- 

 fourths as wide as IV, and one-half as wide as V. Somites 

 V, VI, VII are of about the same width. The clitellar 

 somites XIII to XVII are of about the same width or slightly 

 wider and longer than the others. 



The -prostoniiutn divides somite I entirely, reaching the 

 intersegmental groove I/II. 



Dorsal Pores. — Most anterior dorsal pore is between 

 IV/V. Between II/III and III/IV there are slight depres- 

 sions. 



Spermathecal Genital Zone. — There is one pair of closely 

 approximated papillae in VIII and IX occupying about 

 three-fourths of the ventral side of these somites. The 

 papillae are rosette-like, each with a central depression from 

 which apparently protrude the sexual spermathecal setae. 

 In the posterior margin of IX, in line with setae ab, are two 

 preseptal spermathecal pores. In VIII no such pores are 

 visible. 



P ostclitellar Genital Zone. — There is an oval sunk field in 

 the ventral side of somites XVIII-XX, surrounded by a 

 swollen margin protruding beyond the body line. This 



