440 



PULMONATA STYLOMMATOPHORA 



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



Cretaceous . Principal genera : Chlamydcphorus (shell a 



simple plate, internal), AjJera, 

 Testacella (slug- like, shell ter- 

 minal), Strebelia, Streptostyla, 

 Glandina, Salasiella, Petenia, 

 Pseudosubulina, Stre^jtostele, 



Tomostele, Streptaxis (Fig. 203), 

 Gibljus, Ennea, Daudebardia (Fig. 

 193), Schizoglossa, Guesteria, 

 Aerope, Paryphanta, Rhytida 



„ „„, . ^ ,^,-L. T ^ , (subg. Diplomphalus, Elaea and 



Fig. 294. — A, Ennea {Gibhulma) palanga ^ ^ -^ -^ 



Fer ; A', young of same ; B, Gibbus Phenca.) 



honetianus Fall. ^AU. 2. Sehnitidae. — Shell 



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



central tooth present. Tertiary . Genera : Selenitcs, 



Plutonia, Trigonoclilamys, Pseudomilax (?), Brdhouisia (?). 



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 

 wi^h central tooth tricuspid, laterals bi- or uni-cuspid, marginals 



aculeate. Eocene- -. Genera: Otoconcha, Urocyclus, 3Iaria- 



ella (subg. Tennentict), Parmario7i, Helicarion, Cystopdta, Aspi- 

 delus, Ustria, Vitrinopsis (subg. Vitrinoidea, Parmelld), Damay- 

 antia, Nanina ( = Arioi^hanta, including Paehystyla, Physota, 

 Hcmiplecta, Trochonanina, Euplecta, Orpiella, Xcsta, Macrochlamys, 

 Microcystis, Sitcda, Kcdiella, Durgella, Austcnia, Girasia, Parma- 

 cochlea, Africarion, Sesara, Macroceras, and others), Vitriniconus, 

 Parmacella, Limax (subg. Amalia, and many sections), Vitrina, 

 (subg. Vitrinozonites, Velifera), Zonites (subg. Steiiopus, Moreletia, 

 Mesomphix, Hyalinia, Gastrodonta, Pristilo7na, Poecilozonites, 

 Thyroplhorella). 



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

 helicidan, shield covering all the body. Single genus, Philomycus 

 ( = Tehcnnopliorus), with subg. Pcdlifcra. 



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), 



