Two jXew OllgochcBta from Illinois. 145 



third of the duct has a lumen somewhat flattened and 

 .004: to .008 mm. in diameter, which is lined with a cutic- 

 ular la.ver continuous with the cuticula of the body wall. 

 Its epithelial layer is also continuous with the epithelium 

 of the body wall, the cells becoming- longer in the outer 

 portion of the duct, and partaking of the characteis of 

 the columnar epithelium of that part of the body surface 

 which is immediately adjacent to the prostate pores. 

 The muscular layer diminishes in thickness and disap- 

 pears in the outermost portion of the ducr. 



Usua.llj^ four pairs of these glands are present in 

 somites XXIII-XXVI, a pair in the posterior part of 

 each of these somites opening just outside of the outer 

 setae of the venti-al couple. Tne pore and the two setae 

 are nearly in line, and the distance between the pore 

 and outer seta is about one half as great as that be- 

 tween the two setae. In one example two glands were 

 found in one side of a somite and none in the other, the 

 opening of the second gland being between the setae of 

 the ventral couple, but much nearer the outer one. In 

 another example but three pairs were present — in XXIII 

 XXV. 



If these are prostate glands, — and I can see no reason 

 to think that they are not, — they are very far removed 

 from the male pore, and are of an unusual number. 



Benham has called attention to several features in the 

 striictui-e of S. tamesis as being quite remarkable. In 

 these particulars the resemblance of the new form to 

 that species is striking. (1) The sperm duct has the 

 same superficial position and inconspicuous opening, the 

 only difference being that it does not leave its position 

 at the base of the clitellar layer to pass outward until 

 it reaches the septum between XVIIE and XIX, where, 

 curving quite abruptly, it opens at the male pore upon the 

 ridge already mentioned and opposite the anterior part of 

 somite XIX. (2) In each species a pair of ovisacs 

 occurs in somite XIV, in which were found ova showing' 

 karyokinesis. (3) Longitudinal tegumentary vessels 

 passing forward from somite XIV are present in both. 



