640 APPENDIX. 



in the list, in which the body and shell are sub-globose and dis- 

 tinctly spiral, and in which the central portion of the shell is 

 more or less exposed. The three species, P. punctata, taniata, 

 and reticulata, indicated by Van Hasselt as inhabiting Java, 

 may possibly have to be associated with them. 



The oilier species of Parmacella in the list were at first 

 separated by Dr. Gray to form a new genus, Drusia, but, in a 

 communication with which we have been l'ecently favoured by 

 him, he considers it most probable that, from the similarity of 

 the shell of P. Valencienii to that of Cryptella ambigua, the 

 animal in each case is included in the shell and furnished 

 with an operculum in the young state, and suggests that until 

 the development of these animals shall be observed, it will be 

 better to arrange them with the genus Cryptella, of which 

 Drusia will therefore become a synonym. 



To the genus Cryptella also for similar reasons Dr. Gray, for 

 the present, refers his genus Girasia. 



The species of Cryptella will then stand as follows : 



Alexandrina, Ehrenb. Mauritia, Ferus. 



ambigua, Ferus. Rangiana, Ferus. 



Deshayesii, Moquin-Tand. rutellum, Hutton. 



Gervaisii, Moquin-Tand. Valencienii, Webb and Van 

 Hookeri, Gray. Ben. 



infumata, Ferus. 



With reference, however, to Limax extraneus and proble- 

 maticus, Ferus., which Dr. Gray had referred, with doubt, to his 

 genus Girasia, they probably belong to another distinct genus 

 allied to Limax, which he proposes to call Biyasia. 



Genus HYPSELOSTOMA, Benson. 



(Fam. HELICINiE.) 



Shell convolute, conoidal, umbilicus open, last whorl free, pro- 

 tracted, turned upwards ; aperture trumpet-like and dentate ; 

 peristome horizontal, expanded. 



Syn. Tanystoma, Bens., olim, not Motsclwidtzhj or Latr. 



Ex. H. tubiferum, Benson, pi. 138, fig. 4, 4, a. 



