2 ■ University of Michigan 



Types: No. 38965 Coll. Walker. Cotypes in the collections 

 y. Hirase; Acad, of Nat. Sci. Thiladelphia ; U. S. Nat. 

 Museum and Museum of Zool., Univ. of Mich. 



Compared with C. tcrcbra Bens., the only one of the Indian 

 species which it at all resembles, and of which I have three 

 specimens before me, C. hirasei is longer, narrower, the aper- 

 ture less oblique to the axis, the longitudinal striation is more 

 developed and the spiral lines less conspicuous. 



This most interesting discovery of Mr. Hirase w'as made 

 several years ago and the specific description has been delayed 

 by the desire to obtain alcoholic material so that the systematic 

 position of the genus might, if possible, be determined. 



Camptoceras has hitherto been known by three species, all 

 from India, and its unexi)ected occurrence in Japan widely 

 extends its range. 



The systematic position of the genus has been the subject 

 of very diverse opinions. Benson, who discovered the typical 

 species, gave a brief dcscrii)tion of the external appearance 

 of the animal and compared it with and distinguished it from 

 Lymnsea. Nevill, according to Gude, was of the opinion "that 

 it would prove to be a sinistral form closely allied to Suc- 

 cinea." Chenu placed it near Physa and Fischer did likewise, 

 remarking (Man. Con., p. 511) that, if the eyes, as stated by 

 Benson, w^ere placed at the base of the tentacles, it could not 

 possibly be a terrestrial species. Gude, on the other hand 

 (Fauna Brit. India, Moll. II, 1914, p. 460), followed Nevill 

 and retained it in the family Succineidse. 



Camptoceras hirasei occurs abundantly in Osaka and has 

 been bred in ]\Ir. Hirase's aquarium, so that Benson's original 

 opinion as to its fluviatile character has been demonstrated. 

 Figure 3, drawn from the living animal by Mr. Hirase's artist, 

 shows the characteristic features of an aquatic species. 



