262 E. S. GOODRICH. 



A brain deeply cleft in front, and a nerve-cord bearing 

 muscular strands of considerable size. 



A compact nephridium, the funnel of which is peculiarly 

 modified. 



A pair of testes in the 10th, and a pair of ovaries in the 

 11th segment. 



Two short sperm-ducts, without prostate, opening into a 

 median chamber, which itself opens to the exterior on the 11th 

 segment by a large median pore. Oviducts rudimentary. 



Two pear-shaped spermathecse, opening by a common median 

 ventral pore on the 10th segment. 



An anterior and a posterior sperm-sac, and an ovisac. 



A clitellum extending over the 10th, 11th, 12th, and part 

 of the 13th segments. 



Many of these characters place this little worm in a very 

 isolated position. The dense covering of " sense-hairs," 

 although perhaps of no great morphological importance, is 

 quite unique amongst the Oligochseta. The absence of com- 

 missural vessels again distinguishes it, I believe, from all its 

 allies, except the smallest and lowest, such as ^Eolosoma ; nor 

 is it usual among the Tubificidae, to which Vermiculus is 

 doubtless related, to find strong muscular strands on the 

 nerve-cord. 



As for the nephridium, the ciliated process of the funnel is 

 no doubt of the same nature as the long ciliated processes on 

 the nephridiostome of Nereis (3) ;^ all such structures appear 

 to be specialised processes of the funnel-cells themselves. 

 The presence of cilia in special ampullse, and their absence in 

 the rest of the nephridial canal, is a character which may, I 

 think, prove to be common to all the so-called Microdrili. 

 Such ampullae are certainly present in other Tubificids I have 

 examined, and in the Euchytraeids, to the nephridium of which 

 latter the compact excretory organ of Vermiculus bears no 

 little resemblance. Professor Vejdovsky (6) has described a 

 Planarian, Microplana humicola, in which the nephridia 



1 I once observed in an Enchytrseid long ciliated processes on the nephridio- 

 stome. exactly like those of Nereis above referred to. 



