XXXIV CLASSIFICATION OF HELICES. 



b. Whorls rounded at periphery ; South American 



Polygyratia, p. 81. 



bb. Whorls carinated at periphery ; Papuan region 



Coxia, p. 83. 



aaa. Jaw solid, smooth ; penis sack continued slightly beyond 

 insertion of vas deferens ; duct of spermatheca long; shell 

 globular or depressed-globose; S. African, Dorcasia, p. 172. 



Tribe II, MACROOGONA. 



a. No blind sack or appendiculaon vagina or spermatheca duct. 

 Eggs or young at birth very large, about one-third the 

 diameter of adult shell ; shell with more less reflexed lip, the 

 embryonic whorls distinctly demarked from after growth. 



b. Shell keeled, at least when young, imperforate, 

 finely wrinkled, the embryonic 3 whorls spirally 

 grooved or decussate ; columella short, vertical, its 

 inner edge with a convex lobe or acute fold. Vivi- 

 parous, Seychelles Is. Stylodonta, p. 149. 

 bb. Shell capacious, not keeled ; embryonic whorls 

 over one-third diameter of adult, post-embryonic 

 growth li whorls or less. Aperture large, lip nar- 

 row, dilated at columellar insertion ; columella 

 concave, toothless. Madagascar 



Helicophanta,p. 151. 



bbb. Shell imperforate, globose-depressed or trochoidal, 



not carinated, solid, bright colored; embryonic 



shell about J diameter of adult. Lip broadly 



reflexed, vividly colored Acavus, p. 153. 



aa. No blind sack on vagina or spermatheca duct ; junction of 



nuclear shell with after growth not distinct ; lip expanded or 



reflexed. 



b. Shell acutely keeled, at least when young; lip 

 usually bright colored, the columella widened into 

 a flat plate. Moluccas Fyrochilus, p.I54. 



bb. Shell umbilicate (except in Pcecilostylus), the lip 

 not bright colored, not widened at columella. 

 Madagascar Ampelita, p. 155. 



aaa. Vagina or spermatheca duct bearing a blind sack. Lip of 

 shell narrow or simple. Eggs and embryonic shell smaller. 

 b. Shell Helicoid, umbilicate, wider than high. 



