1887.] ANATOMY OF KARTHWORMS. 373 



The genus Eudrilus was first described by M. Perrier', who, 

 ho«eYer, liad only ill-preserved material to work at, consequently 

 his account of tlie structure of the worm is imperfect ; it is very 

 evident, nevertlieless, from what he has written upon the subject, 

 that Eudrilus is one of the most remarkable genera of Lumhricidse, 

 and I was particularly glad to liave the opportunity of studying its 

 structure in really well-preserved specimens. 



The most important facts which I have to bring forward in the 

 present paper concern the structure of the female generative appa- 

 ratus. In a note communicated to the ' Zoologischer Anzeiger' ^, I 

 pointed out that Perrier's description of these organs was inaccu- 

 rate — that it did not, at least, apply to the species (a native of New 

 Caledonia) studied by myself. Perrier was right in stating that the 

 ovary was connected with the spermatheca, and that its contents 

 were set free by passing down the duct of the spermatheca ; but he 

 overlooked the fact that the ovary, although apparently sessile upon 

 tlie duct of tlie spermatheca, was in reality connected witli it by its 

 own duct, a long coiled tube. This latter structure did not indeed 

 escape the attention of Perrier; but he erroneously regarded it as a 

 mere diverticulum of the spermatheca, and failed to make out its 

 connection with the ovary. I «as inclined to regard the species of 

 Eudrilus'^, upon which my own investigations were made, as distinct 

 from any of those which Perrier has described. On this account I 

 held it possible, though not probable, that Perrier and myself were 

 both right, and that the discrepancies between our observations 

 might be explained by supposing a real difference, as regards the 

 points at issue, between the two species. Now tliat I have been 

 able to study a second species of Eudrilus, I am disposed to think 

 that Perrier was entirely wrong in his description. 



§ External Characters. 



The Eudrilus which forms the subject of the present paper is a 

 small worm, not measuring more than 32 millim. in length. It is 

 remarkable for the fact that the body is built up of very few seg- 

 ments ; I counted 4J, 4.5, and 46 respectively in each of the three 

 specimens at my disposal. 



The colour of the worm is a dark bluish purple upon the dorsal 

 surface, fading into a dull yellow upon the ventral surface. 



The setce are disposed in pairs, as in Lumbricvs. I did not 

 notice any tendency to an increased number in any of the pairs 

 which Perrier has referred to. 



The clitellum occupies segments 14-18 inclusive. 



The nephrirliopores are placed in front of the ventral pair of 

 setse ; in all other species of this genus the nephridial apertures are 

 related to the dorsal pair of setse. 



The female generative pores are a pair of conspicuous orifices 

 situated upon the 14th segment, and in front of the dorsal pair of 

 setae. 



> Nouv. Arch. d. Mus. t. vhi. (1872) p. 71. * No. 224 (1886). 



* Proc. Zool. Soc. May ISth, 1886, p. 302. 



