Sjpecits of North American Oigochceta. 400 



ciliated funnels of the sperm-ducts have tbe usual situ- 

 ation in X and XI. The sperm-duets are slender and 

 without convolutions. They meet in XII and extend to 

 XVII, those of either side h'ing close to each other and 

 passing through each somite just laterad of seta 2 {sp. 

 d., PI. XXXVIIL, Fig. 14). During their course they 

 lie upon the muscle layer of the body wall, without en- 

 tering it, until they are in the neighborhood of the male 

 pore. When they have reached the vicinity of the penial 

 setae they enter the muscular wall and unite, and the com- 

 mon duct passes around the posterior side of the duct 

 of the prostate gland and the outer penial seta and 

 opens to the exterior between, and slightly posterior to, 

 the penial setae (PI. XXXVIIL, Fig. 15 and 16). One 

 pair of prostate glands is present in XS^II. The glandu- 

 lar part is tubular and slightly smaller in diameter in 

 the distal region, where it is bent, but not helix-like. 

 More frequently the distal portion projects into XVI II. 

 The wall is composed of long glandular cells, of which 

 many are somewhat bent and irregular. Although I 

 have studied thin sections carefully, I can distingu'sli no 

 differentiation into two layers. If there is any inner 

 epithelial layer at all, it is very slightly developed and 

 not continuous. I have found the same condition in 

 sections of each of several individuals. The musculai* 

 duct is slightly longer than the setal sac near it, and 

 opens to the exterior just outside the outer peuial seta. 

 The penial setae and the pore of the duct of the pros- 

 tate are very nearly in a straight line, with the male 

 pore between the setae and the prostate-duct pore just 

 outside the outer penial seta (Fig. 15 and 16). One 

 pair of spermathecse is present in IX. In some speci- 

 mens one spermatheca projects into VIII, but the pores 

 are upon IX in each instance. These pores are at the 

 anterior margin of the somite and in line with seta 1. 

 The spermathecae extend from one third to one half 

 the way across the somite, each having a somewhat 



