264 CALIFORNIA ACADEMY OF SCIENCES. 



RoscE and agricola. But the relative length is not the 

 same. In O. contractus this muscular swelling of the 

 sperm duct is as long as the muscular part of the prostate, 

 while in O. Rosce this part is about one-fourth to one-third 

 smaller than the muscular part of the prostate. 



The lumen also is wider in this species than in O. Rosce. 

 In O. contractus the lumen is considerably wider than the 

 narrow part of the sperm duct, while in O, Rosce the 

 lumen is narrower than the sperm duct proper. In O. 

 contractus the lumen occupies about one-third of the en- 

 largement, while in O. Rosce it occupies onl}- about one- 

 sixth or one-seventh. The enlargement consists of 

 two additional layers, one exterior of transverse muscles, 

 which part is ver}- thin, and one interior of longitudinal 

 rhomboid cells, arranged obliquely. 



The prostate is long, cylindrical, not tapering, with a 

 long muscular lower duct, of similar form and construc- 

 tion as in O. Rosce. This muscular part of the prostate 

 is of the same length or slightly shorter than the muscular 

 part of the sperm duct. The glandular part of the pros- 

 tate is shorter than in O. Rosce, or about one and one-half 

 times larger than the muscular part. In O. Rosce it is 

 over twice as large as the muscular part. 



The ovary is in xiii and the oviduct in somite xiv, as 

 usual. The ovary, affixed to the anterior septum, con- 

 tains very large globular or circular ovae. The oviduct 

 is almost straight, gradually increasing in size towards 

 the funnel, which is not distinctly set, widened or re- 

 flected. 



The cephalic g-a)ig'lion is in somite iii, and the infra- 

 pharyngeal ganglion, which is ver}- large, is between 

 somites iii and iv, as usual. 



Habitat, in pools close to the road, near Llano Grande, 

 in Guatemala, Central America. 



