PUPISOMA. 21 



lusks; but there is good reason for the belief that the normal 

 areas of some Pupisomas have been extended by commerce. 

 Living on the bark and leaves of a great variety of shrubs 

 and trees, some of them such as oranges and palms, widely 

 cultivated, these snails must often be transported to remote 

 gardens in different parts of the world. Burimp considers 

 the South African species to be such involuntary immigrants. 

 Possibly the New Caledonian and Queensland forms may 

 also be expatriated species from India or elsewhere. How- 

 ever, the details of distribution of Pupisoma are as yet little 

 known in South America, tropical Africa, the East Indies, 

 and even India. 



Besides the widely-spread species dioscoricola and orcula, 

 there are various more local species in America and Asia. 



In America the only group which could well be thought 

 related to Pupisoma. is Bothrwpupa. This genus has been 

 placed in the Gastrocoptinae (Vol. XXIV, p. 226), but with 

 some doubt. If the animal proves to lack lower tentacles, as 

 I suspect, it will be transferred to the subfamily Vertigininse, 

 in the neighborhood of Nesopupa. It is possible that the 

 pitted-granulose American Pupisomas are simplified, foli- 

 colous derivatives from a Bothriopupid ancestral stock. Ob- 

 servations on the living animals of these snails will bring the 

 several hypotheses of their affinities nearer the earth. 



Some Thysanophoras resemble Pupisoma; yet upon going 

 over the shells carefully there is no serious difficulty in mak- 

 ing the distinction. P. dioscoricola, under various names, has 

 hitherto been referred to Thysanophora or Acanthimda. 



Pup'isoma as now accepted contains three sections which 

 appear related by shell characters. 



I. Pupisoma. proper. Shell ovate, somewhat pupiform, of 

 41/2 to 5 whorls, minutely pitted-granose ; columella. thick- 

 ened, obliquely truncate or indistinctly toothed. P. Ugnicola,, 

 P. evezardi; both Indian. 



II. In a tropical American group the shell is minutely 

 pitted-granose, otherwise like Ptychopatula. Species, P. mac- 

 neilli, P. minus, P. medwmericanum. The sculpture resem- 



