400 Illinois State Laboratory of Natural History. 



ent in VII, attached to the ventral wall, just posterior 

 to the spermathecse (Plate XXXV., Fig. 4). The c liated 

 funnels of the speiin-duct are in the posterior part of 

 the same somite, and are quite large, simple, and fun- 

 nel-shaped, and have their opening directed dorsad (PI. 

 XXXV., Fig. 3 and 4). The sperm-duct is short and wide. 

 After entering VIII its course is dorsad, but making a 

 rather short turn it passes ventrad, opening upon the 

 same somite. The walls of the first half of the duct are 

 glandular (PL XXXV., Fig. 3), and those of the last 

 half are muscular. The ventral wall of VIII is much 

 thickened in the vicinity of the male pore. The opacity 

 due to the clitellum renders the study of the duct im- 

 possible in the living specimen, and I have had to de- 

 pend upon sections for my knowledge of it. In the 

 specimens sectioned there is no especial enlargement of 

 the lumen to form an atrial chamber. The cavity of 

 VII contains loose spermatozoa, and a single sperm- 

 sac opens from it and extends through VIII into IX^ 

 Wing dorsad to the alimentary tract. Ova are contained 

 in IX. A pair of ovaries is situated in VIII, and there 

 seem to be oviducal pores at VIII | IX. In the most an- 

 teiior part of VII is a pair of spermathecse, the pores 

 of which are at the anterior margin of that somite. (PI. 

 XXXV., Fig. 1, 2, and 4.) 



The asexual reproduction or budding of P. leidyih't^ in 

 some respects quite different from that observed by 

 Bourne in the species studied by him ('91, p. 354). 

 Unfortunately, I have not been able to obtain any 

 data concerning this phenomenon in P. longiseta. P. 

 leidyi agrees with other naidiform worms in the gen- 

 eral features of the budding process, new somites being- 

 developed at the budding zone, an indefinite number of 

 which form the posterior part of the anterior daughter 

 worm, and a definite number (z' of Bourne, '91, p. 

 339) the anterior part of the posterior daughter 

 worm ; but instead of there being a constant, or nearly 



