AN ATTEMPT TO CLASSIFY EARTHWORMS. 283 



Somite xiv, where it divides into two short processes^ one to 

 each oviduct. In Somites xvi and xviii there arelong^ paired, 

 blind processes from the spermatheca. These remind one of 

 the elongated ovisacs of the water-worms. This is the only 

 form known with spermathecal aperture behind the male pore, 

 and it appears to me to be doubtful whether this sac is homo- 

 logous with the spermatheca of the ordinary type. Michaelsen 

 makes no statement as to its contents. It may be, though he 

 gives no grounds for this supposition, that the oviducts are in 

 a state of degeneration, and that the '' spermatheca " serves as 

 an enlarged ovisac, in which perhaps the ova are fertilised and 

 retained during development. In fact, the worm may be ovi- 

 parous. 



Species. — P. coeruleus. 



6. Stuhlmannia. 



Setae four couples. 



Clitellum on Somites xiv to xvii. 



Male pore median in Somite xvii. 



Spermathecal pore median, single, in Somite xiii. 



Ovipores in Somite xiv. 



Two long prostates extending from Somites xvii to xxiv, 

 and uniting in xvii. 



Median spermatheca ; from its proximal end a pair of out- 

 growths surround the intestine and meet dorsally. 



Oviducts communicate with the spermatheca. 



These structures are so complicated, and so brief a descrip- 

 tion of them is given, that I have not attempted to construct a 

 diagram. 



Species. — S. variabilis. 



Of these six genera, all but one — viz. Callidrilus — are 

 probably referable to the family Eudrilidse, mihi. The 

 exception appears to belong to the family Rhinodrilidae, 

 mihi, although it presents one or two points in which it does 

 not agree with my diagnosis of the family, e.g. position of 

 male pore and of nephridiopores. Michaelsen gives no details 

 as to the structure of what he called " prostate," and it may 



