The Nautilus. 



Vol. VII. JUNE, 1893. No. 2 



SOME NOTES ON ZONITIDAE. 

 BY DR. V. STERKI. 



1. The generic name Zonites Montf., has, by European malacolo- 

 gists, long ago been restricted to a group of circu in-Mediterranean 

 forms, such as algirus, vertlcillus, gemonensis, etc., none of them 

 being represented in the recent North American fauna ; and as it 

 seems to be a well-defined genus, we will do well to recognize this 

 restriction of the group. The old genus Zonites, or Hyalinia, is 

 being disintegrated, just as the old genus Helix has been. For 

 nitidus Miiller, the genus Zonitoides has been established on charac- 

 ters chiefly anatomic, the presence of a dart sac and dart, and, as it 

 seems, peculiarities of the radula. As the same dart sac and dart is 

 present in a number of North American species, such as elliotti, 

 Ugerus, demissus, intertextus, gularis, suppressiis, internus, etc., and, 

 as has been supposed, and I can positively confirm, arboreus — they 

 would range under Zonitoides, especially if their anatomy prove to 

 agree with nitida, also otherwise. Dr. v. Ihering makes the propo- 

 sition to unite all Vitrino-zonitidae having a dart^ in a family, as 

 xiphogone forms — "Zon." (or Hyal.) fulvus Miill., gimdlachi Pfr., 

 sterkii Dall., belong to the genus Conulus Fitz., well characterized 

 anatomically. Hy. crystaUina MiilL, dicvphana Studer., etc., of the 

 old continent, have their peculiar anatomy also, and range under 



1 Which, however, is not homologous with the dart of the Helicidae, and there- 

 fore named pttgio, by v. Ihering. 



