INTRODUCTION. IX 



The upper subfamilies in this diagram are relatively evolved 

 groups which have lost penial accessories. In Pupillidae I 

 fail to trace any relation whatever between penial complica- 

 tion and the development of apertural armature, since four of 

 the five subfamilies contain forms with highly complicated, 

 together with others having toothless apertures. 



Subfamily Gastrocoptinae. 



Gastrocoptinae Pilsbry, 1918, p. x. Includes Chrondrinidae 

 Steenberg, 1925, p. 201. 



Shell varying from minute to the largest of the family, 

 typically with 5 teeth, the angular and parietal more or less 

 converging or concrescent; but varying to forms with many 

 accessory teeth or with no teeth. 



Animal oviparous, without penial accessory organs. Jaw 

 as in Pupillinae; 



This subfamily is retained in the limits assigned in Manual 

 1916-1918 except for the genus Bothriopupa, which was re- 

 moved to the Vertigininae near Nesopupa in 1926 (vol, 27, 

 p. 228). 



The genera were originally classified in four series. Those 

 of my fourth group had already been brought into sequence 

 by Pfeiffer, 1878. Steenberg (1925) formed the family 

 Chondrinidae for Chondrina, Ahida and Sandahlia, which he 

 dissected, but H. Burrington Baker in this volume has shown 

 that Oastrocopta agrees essentially with the European genera 

 mentioned. 



In genera starred the genitalia have been examined. 



1. Gibbulina, 24:5. Chaenaxis, 24:1. *Gastrocopta, 24:6. 



2. Hypselostoma, 24:175. Boysidia, 24:192. Gyliotrachela, 

 24:210. 



3. Aulacospira, 24:220. Systenostoma, 24:224. 



4. Fauxulus, 24:234. Odontocyclas, 24:254. *Sandahlia, 

 24:250. *Abida, 24:262. Granopupa, 24:332. *Chondrina 

 (Modicella), 25:1; 27:283. 



Dr. H. B. Baker contends that the name Chondrina is in- 

 admissible under the rules, and should yield to Modicella; 

 see page 203. 



