1901.] NATURAL SCIENCES OF PHILADELPHIA. 647 



CATALOGUE OF THE CLAUSILIIDJE OF THE JAPANESE EMPIRE. 1 

 BY HENRY A. PILSBRY. 



The general sequence of species in the following list is from 

 primitive to specialized forms; but this end is only imperfectly 

 attained, as there are several highly specialized groups terminating 

 wholly independent phyla, making a serial arrangement quite 

 arbitrary. The forms with narrow clausilium and several palatal 

 plicae in place of a lunella are the more primitive, retaining the 

 structure of early Tertiary groups. Meg alop heed usa and the typi- 

 cal Hemiphcedusce are of this kind. Zaptyx, Luchuphcedusa and 

 Ti/rannophcedusa seem to be three independent specializations from 

 an early Hemiphredusan stock. Stereophcedusa stands a little more 

 remote; while Pseudonenia, Euphcedusa and Reinia probably 

 separated from the pro-Hemiphsedusan stock at a still earlier period. 



The East Asiatic Clausiliidw are much more closely related to 

 early Tertiary than to modern European groups. The evidence 

 indicates that, like the Belogonous Helicidce, a common stock of 

 Clausiliidce spread over Asia and Europe, at least as early as the 

 Eocene. Subsequent evolution has been along independent lines 

 in the East and the West; and just as I have demonstrated in the 

 Helicidce, the European stock has forged ahead, while the Oriental 

 looks backward, many a group retaining old characters. 



Ninety-three well-established species of Clausilia are now known 

 from Japan, more than half of them first described in this journal. 

 Of this number forty-four were brought to light by Mr. Hirase. 

 The localities of many others, previously uncertain, have been 

 ascertained from specimens collected by him. In addition to these 

 species, thirty-five subspecies or varieties have been described. 

 The list of species is encumbered with eleven additional specific 

 names, standing for forms so inadequately described that their rela- 

 tionships with other species are not ascertainable from published 



1 Exclusive of Formosa. 



