2o8 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



of about the same size. The distal sac is of the usual 

 structure, with columnar epithelium. The narrow, lower 

 part of the spermatheca, as well as the diverticle, is of a 

 different structure, the walls consisting of a continuous row 

 of small pockets separated by long, narrow cells. In these 

 pockets are packed bundles of spermatozoa, the heads of 

 which are attached to the bottom wall of the pockets. At 

 the junction of the narrow and the sac-like parts of the 

 main diverticle are found a few cells of the same peculiar, 

 globular form as those found to be so numerous in Trigaster 

 tolteca. It is evident that the structure of the lower parts 

 of the spermatheca is similar in Trigaster Lankesteri and 

 Z . mneca-mecce , as Benham also describes the spermatozoa 

 as being attached to the lower part of the diverticle. The 

 pores of the spermathecse are situated half-way between 

 the setae and the anterior septum, but in the intersegmental 

 grooves. The septa are not connected with the grooves, 

 but are situated much farther forward. 



The sperm-sacs are very large and extend all around the 

 intestine. 



The testes and sperm-funnels offer nothing characteristic. 



The sperm.-ducts are completely hidden in the longitudinal 

 layer of the body-wall, just as in T. tolteca. As Benham 

 did not find any sperm-ducts in T. Lankesteri, it is probable 

 that in that species also the sperm-ducts are hidden in the 

 body-wall. 



The prostates are very thin and folded repeatedly. Their 

 glandular part is many times longer than the muscular duct 

 which appears to be unusually short. The prostates are 

 confined to one somite each, and are composed of two 

 distinct layers of cells. 



BENHAMIN^. 



Benhamia Michaelsen. 



Of the species and varieties described under this genus 

 none equals in interest Benhamia viridis. This species 

 seems to be a native of Mexico and not an imported worm. 



