PUPILLID.E. XI 



This subfamily is related to the Pupillincc (q. v.}, but dis- 

 tinguished by the different arrangement of apertural teeth of 

 typical forms in all the genera. As most genera have also 

 series which are catamorphic or degenerative in teeth, differ- 

 ential diagnosis of these subfamilies are not now practicable. 

 Nevertheless, a study of the more fully toothed forms of each 

 genus shows that the subfamily is a natural group. 



The genera of Gastrocoptincu fall into four collateral series, 

 as follows : 



I. Small (length 4 mm. or less, 4 to 6% whorls), thin, cor- 

 neous or brown. 



THE GASTROCOPTA GROUP. Pupiform; angular and 

 parietal lamellae converging or united. 



Gibbulina, p. 5. South America. 



Chccnaxis, p. 1. North America. 



Gastrocopta, p. 6. Nearly world-wide. 



Bothriopupa, p. 226. Tropical America. 

 THE HYPSELOSTOMA-BOYSIDIA GROUP. Pupiform, conic 

 or depressed, last whorl tangential (p. 172). 



Hypselostoma, p. 175. Oriental. 



Boysidia, p. 192. Oriental. 



Gyliauchen, p. 210. Oriental. 



THE AULACOSPIRA GROUP. Helicoid, the last whorl not 



tangential (p. 220). 

 Aulacospira, p. 220. Philippines. 

 Systenostoma, p. 224. Indo-China. 



II. Mainly larger, more solid shells of cylindric, conic or tur- 

 rited form, usually with more whorls, which are more 

 closely coiled than in the preceding groups. 



THE ABIDA GROUP (p. 232). 



Fauxulus, p. 234. South Africa. 



Odontocyclas, p. 254. Eastern Alpic region. 



Sandahlia, p. 258. Pyrenees. 



Abida, p. 262. Europe. 



Granopupa, p. 332. Mediterranean countries. 



Chondrina (Vol. XXV). Europe, Morocco. 



'fi*fASS^ 



