1 66 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 3D Ser. 



and I think it is best to keep species with three gizzards 

 out of that genus. The completely hidden nature of the 

 sperm-ducts is also an interesting feature of the genus, 

 which character it shares with Trigaster . To join Za^o- 

 tecia with Benhamia is even less natural. With the genus 

 Trigaster there is a greater affinity and at first I had 

 arranged the species under that genus; but it now seems 

 to me more proper to keep meganephric and plectonephric 

 species apart, except in cases where we know with cer- 

 tainty that great variation exists in their structure, as for 

 instance, in Dichogaster. 



In a preliminary paper (Eisen 22) have been noted in a 

 general way the characteristics of various species of Diplo- 

 cardia which have been examined critically. Through 

 the kindness of Professor Frank Smith of the State Bio- 

 logical Laboratory of Champaign, Illinois, I have been 

 enabled to study the specimens of all the Diplocardia spe- 

 cies in his possession, and have made observations on 

 some points which previously had been either overlooked or 

 misunderstood. 



Professor Smith has also had the kindness to call my 

 attention to a couple of errors in the above mentioned 

 paper. The species of Diplocardia so far known are 

 remarkably well characterized for identification, differing 

 strikingly in the external genital zones as well as in their 

 inner organization. The median ventral zone around the 

 prostates is well marked, but I think too much significance 

 should not be placed on the presence or absence of papillae, 

 there being considerable variation in different specimens. 

 Of more importance is the form and size of the zone, the 

 curvature and shape of the sexual grooves between the 

 prostates, the size and ornamentation of the penial and 

 spermathecal set«, the location of the spermathecal pores, 

 etc. 



By courtesy of Professor Albert Koebele I add the 

 description of a new species, characterized by the posi- 

 tion of the male pores in somite XVIII. This raises the 



