Species of North American OUgochcBta, 399 



The perivisceral corpuscles are very conspicuous, a fact 

 which is due to the presence of several spherical bodies 

 that nearly hll the cell. The corpuscles are spherical and 

 collected chiefly about the inner ends of the setai. 



In the latter part of July of the present year, 1896, 

 among a large number of specimens without clitellum 

 and sexually immature, I found one individual which had 

 organs in VII and VIII, presumably gonads. I have 

 as yet found no sexually mature specimens of P. leidyi 

 in their natural environment, but in the latter part of 

 May of the present year I found a few of them among 

 the progeny of an iadividual of this species which 

 had been isolated in December of last year and kept 

 with its descendants in confinement at the temperature 

 of an ordinary living room. These worms exhibit uni- 

 formity in their reproductive organs, and as they also 

 agree with the specimens above referred to in the pres- 

 ence of organs in VII and VIII, I have no reason for 

 thinking that their repi'oductive organs are not normal. 

 My sections, and my observations upon the living speci- 

 mens enable me to establish several important points 

 concerning them. The most noticeable difference between 

 the reproductive organs of Pristina and those of other 

 Naidomorpha in which these structures have been studied, 

 is the fact that they are located two somites further back 

 in Pristina than in other members of this family. 



In P. leidyi the clitellum extends from the setae of VII 

 to those of IX, and is quite thick upon the dorsal por- 

 tion of VIII and the anterior part of IX. In place of 

 the ordinary ventral setae in each side of VI a pair of 

 genital setae appears, as previously stated. Ventral 

 setae of the usual type are present upon each of the 

 neighboring somites. A pair of large multicellular glands 

 without definite lumen is situated in the posterior part 

 of VI. Each of these glands is connected with the ven- 

 tral wall of the coelom and surrounds a pair of genital 

 setae (PI. XXXV., Fig. 1 and 4). A pair of testes is pres- 



