THE GASTROPODA 189 



FAMILY 1. OLEACINIDAE, Adams. Shell oval, elongated, with a 

 narrow aperture ; neck very long ; labial palps prominent. Genera 

 Oleacina, Bolton ( = Glandina) ; aperture truncated anteriorly ; colnmella 

 smooth. Streptostyla, Shuttle worth ; columella with a fold ; aperture 

 elongate, not truncated anteriorly. FAMILY 2. TESTACELLIDAE, Gray. 

 Shell globular or auriform, external or partly covered by the mantle. 

 Genera Streptaxis, Gray ; shell external, heliciform, the last whorls 

 generally set obliquely to those first formed. Gibbulina, Beck ; shell 

 cylindrical, umbilicated. Aerope, Albers ; shell external, globular, with a 

 small umbilicus ; radular sac enormous ; from South Africa. Rkytida, 

 Albers ; shell depressed, with a very wide umbilicus ; from New Zealand. 

 Daudebardia, Hartmann ; shell coiled, only occupying the posterior part 

 of the body ; animal limaciform ; the genital orifice situated between the 

 right tentacle and the shell (Fig. 172, B). Testacella, Cuvier (Fig. 172, C) ; 

 shell small, auriform, situated at the posterior extremity of the limaciform 

 body ; genital orifice near the right tentacle. Chlamydophorus, Binney ; 

 shell plate-shaped and nearly completely covered by the mantle. Schizo- 

 ylossa, Hedley. FAMILY 3. RATHOUISIIDAE, Heude. Animal naked, 

 devoid of a shell, with a carinated mantle covering the whole body ; male 

 and female orifices distant ; the female orifice near the anus. Genera 

 Rathouisia, Heude. Atopos, Simroth. 



TRIBE 3. ELASMOGNATHA. 



The jaw with a well-developed dorsal appendage. 



FAMILY 1. SUCCINEIDAE, Chenu. Anterior tentacles much reduced ; 

 male and female orifices contiguous but distinct ; shell thin, spiral, with 

 a short spire. Genera tiuccinea, Draparnaud ; shell external, oblong, 

 with a large aperture ; British. Homalonyx, d'Orbigny ; shell auriform, 

 the spire scarcely projecting ; the edges of the shell covered by the 



Fio. 178. 



Antitea macdonaldi, Gray, left-side view, pct.f, pallial cavity; ps, pneumostome ; t, 

 tentacle. (After Mac Donald.) 



mantle ; animal limaciform ; American. Hyalimax, Adams ; shell oval, 

 wholly internal". Neohyalimax, Simroth. FAMILY 2. JANELLIDAE, Gray. 

 Limaciform animals, with an internal rounded shell ; the mantle very 

 small and triangular ; the pulmonary chamber with tracheae ; no anterior 

 tentacles. Genera Janella, Gray. Aneitella, Cockerell. Aneitea, Gray 

 (Fig. 178). Triboniophorus, Humbert. All from the Australo-Zelandic 

 region. 



TRIBE 4. DITREMATA. 



Male and female genital orifices distant (Fig. 59, o.f, o.m). 



FAMILY 1. VERONICELLIDAE, Gray. Terrestrial, naked, limaciform 



