234 



RADULA OP^ PULMONATA 



CHAP. 



includes Anostoma, Odontostomus^ BuUminus, Vertigo, Strophia, 

 Holospira^ Clausilia, and Balea. 



Stenogyridae^ including Achatina, Stenogyra^ and all its sub- 

 genera: Central tooth small and narrow, laterals much larger, 

 tricuspid, central cusp long, marginals similar, but smaller. 



Acliatinellidae : Two types occur ; (a) teeth in very oblique 

 rows, central, laterals, and marginals all of the same type, base 

 narrow, head rather broad, with numerous small denticles 

 (^Acliatinella proper, with Auriculella and Tornatellina, Fig. 



Fig. 140. — Portions of the radula of A, Hyalinia nitidula Drap., Yorkshire, with 

 central tooth, first lateral, and a marginal very highly magnified; B, Helix 

 poinatia L., Kent, showing central tooth, laterals, and one extreme marginal, 

 the two former also highly magnified; C, Orthalicus tmdatus Bvng., Trinidad, 

 with three laterals highly magnified ; D, CyUridi^ella rosea Pfr., Jamaica, central 

 tooth and laterals, the same very highly magnified ; E, Achatinellavulpina Fer., 

 Oahu, central tooth (c) and laterals, the same highly magnified. 



140, E) ; (5) central tooth small and narrow, laterals bicuspid, 

 marginals as in Helix (^Amastra and Carelia). 



Succineidae : Central and laterals helicidan, bi- or tricuspid 

 on a quadrate plate, marginals denticulate on a narrow base ; 

 jaw Avith an accessory oblong plate. 



Janellidae : Central tooth very small, laterals and marginals 

 like AchatineU'idae (a). 



Vaginulidae : Central, laterals, and marginals unicuspid 

 throughout, on same plan. 



Oyicliidiidae : Rows oblique at the centre, straight near the 



