1898.] NATURAL SCIENCES OF PHILADELPHIA. 67 



4 



ANATOMICAL NOTES ON CERTAIN WEST AMERICAN HELICES. 



by h. a. pilsbry and e. g. vanatta. 1 



The genus Glyptostoma. 



This genus has very distinct conchological features, the shell re- 

 calling the typical Zonites in form. The jaw, radula and genitalia 

 have been investigated and figured by W. G. Binney. From 

 these data the senior writer placed Glyptostoma in the group Belo- 

 gona Euadenia of the arrangement of Helices given in volume IX of 

 the Manual of Conchology, near the genus Epiphragniophora. We 

 have now examined two specimens of G. Newberryanum. The genital 

 system of one is figured on PI. I, fig. 1. The two examples dis- 

 sected agree perfectly in all details, but in several points do not 

 correspond with Binney's figures. The right eye is retracted be- 

 tween $ and 9 branches of the genitalia. The penis is continued a 

 short distance beyond the insertion of the vas deferens, and may be 

 regarded as having a rudimentary epiphallus, the long retractor 

 inserted thereon distally. There is no trace of a flagellum. Vagina 

 long, at its apex the very long duct of the spermatheca enters. This 

 duct is of the length of the uterus and terminates in a large globular 

 spermatheca. No diverticulum. At the point where the sp. d. 

 enters, an ovate sessile body is placed. This has the shining, fleshy 

 muscular substance commonly seen in dart sacks ; and we do not 

 doubt that the organ is of that nature, although no dart was found in 

 either of the two individuals dissected. The lumen presented 

 several broad folds, and no distinct apical papilla. There is no trace 

 of mucus glands. The talon is unusually long. 



From these characters it appears that the genus, while probably 

 belonging with the series of American dart-bearing Helices, is 

 extremely isolated. The other American genera, Epiphragmoph- 



1 The dissections and drawings of all species noticed in this paper are by 

 Mr. Vanatta, who is also responsible for all anatomical details of the several 

 forms. The more general discussions relating to the systematic bearings of 

 the facts developed are by Mr. Pilsbry. 



We would here acknowledge our indebtedness to Professor W. H. Dall for 

 alcoholic specimens of several of the forms discussed below. 



