440 



PULMONATA — STYLOMMATOPHORA 



to this group), radula with usually few, large, sickle-shaped 

 teeth (p. 232), shell variable, rarely absent, usually external. 



Cretaceous . Principal genera: OhlamydepJiorus (shell a 



simple plate, internal), Apera^ 

 Testacella (slug-like, shell ter- 

 minal), Strehelia^ Streptostt/la, 

 Glandina, Salasiella, Petenia, 

 Pseudosuhulina^ Streptostele^ To- 

 mostele^ Streptaxis (Fig. 203), 

 Grihhus^ Ennea^ Daudebardia 

 (Fig. 193), Schizoglossa^ Gueste- 

 ria^ Aerope, Paryphanta^ Rhytida 



Fig. 294.- a, Ennea (GibbuUna) pa- (s^^' ^iplomphalus, Elaea and 

 langa Fer; A', young of same; B, Rheneo). 

 Gmuslyonetianus F^ll. ^^^ 2. S eUnitid a e. -Shell 



internal, external, or absent ; jaw present, radula Testacellidan, 



central tooth present. Tertiary . Genera: Selenites, Plio- 



tonia^ Trigonochlamys^ Pseudomilax (?), Rathouisia (?). 



Fam. 3. Limacidae. — Shell present or absent, internal or 

 external, spiral or not, tail often with a mucus pore, jaw (Fig. 

 107 A, p. 211) with projecting rostrum on cutting edge, radula 

 with central tooth tricuspid, laterals bi- or uni-cuspid, marginals 



aculeate. Eocene . Genera: Otoconcha^ Urocyclus^ Maria- 



ella (subg. Tennentia'), Parmarion, JTelicarion, Cystopelta, Aspi- 

 delus^ Estria^ Vitrinopsis (subg. Vitrinoidea^ Parmelld)^ Damay- 

 antia, Nanina (= Ariophanta^ including PacJiystyl'a^ Rhysota^ 

 ITemiplecta, Trochonanina, Euplecta, Orpiella^ Xesta, Macro- 

 chlamys, Microcystis, jSitala, Kaliella, Durgella^ Austenia, Girasia, 

 Parmacochlea, Africarion, Sesara, Macroceras^ and others), Vi- 

 triniconus, Parmacella, Limax (^whg. Amalia and many sections), 

 Vitrina (subg. Vitrinozonites, Velife7'a'), Zonites (subg. Stenopus, 

 Moreletia, Mesomphix, Hyalinia, Gastrodonta, Pristiloma, Poe- 

 cilozonites, Thy rophor ella). 



Fam. 4. Philomycidae. — Shell absent, jaw limacidan, radula 

 helicidan, shield covering all the body. Single genus, Philo- 

 mycus (= Tehennophorus), with subg. Pallifera. 



Fam. 5. Helicidae. — Shell present or absent, internal or ex- 

 ternal ; jaw of various types, radula with central tooth tricuspid, 

 equal in size to the first laterals, laterals bi- or tri-cuspid, margi- 

 nals smaller, cusped. Eocene . Principal genera : Oopelta 



(no shell), Arion (shell absent or formed of calcareous granules), 



