CLASS IV 



GASTROPODA 



567 



Family 2. Ringiculidae Meek. 



Inopemdate forms resembling the Actaeonidae in having columellar folds. Creta- 

 ceous to Recent. 



Ginulia Gray (Fig. 1061). Globose, inflated, spirally grooved or punctate. Spire 

 short ; ajjerture crescentic ; outer lip reflected and thickened. Columella and inner lip 

 with numerous transverse folds. Cretaceous. 



Subgenera : Avellana, Ringinella d'Orb. ; Eriptycha Meek ; Fortisia Bayan. Eocene. 



Ringicula Desh. (Fig. 1062). Small, ovoid to globose, thick-shelled, with manimil- 

 lated protoconch. Spire short ; body whorl large, usually smooth. Ajjerture canal- 



Fi(i. 1061. 



A, Cinulia {AvcUana) incrasstata (Mant.). Gault ; Perte du 

 Rhone. B, C. (RhigineUa) Uwhryma Mich. Gault; P^olkestone, 

 England. C, ('. {Eriptycha) drcurtnla Zekeli. Turonian ; Gosau, 

 Austria. 



Fiti. 1002. 



Ringicula hoernesi 

 Seguenza. Miocene ; 

 Steinabrunn, near 

 Vienna. 



iculate jiosteriorly, excan^ated anteriorly. Columellar border thick and callous ; the 

 columella arched, and furnished with from two to four plications. Outer margin 

 usually very thick, reflected, and occasionally denticulated within Cretaceous to 

 Recent. 



Pugnus Hedley. Cylindrical, with sunken S2)ire. Recent. 



Family 3. Akeratidae Pilsbry. 



Shell oval or cylindrical, thin and fragile, the spire low or concealed. Tertiary and 

 Recent. 



Akera Miiller (Fig. 1063). Thin-shelled, flexible, with ex])osed, truncated spire. 

 Whorls separated from one another by deep sutures. Sutures 

 deep and prominent ; outer lip separated from the sjjire. 

 Eocene to Recent. 



Haminea Leach. Oval, thin -shelled, brittle; the spire 

 concealed. Tertiary and Recent. 



Fig. 1003. 



Akera striatella Lam. 

 Oligocene ; Castel Goniberto, 

 near Vieenza. 



Family 4. Hydatinidae Pilsbry. 



Globose or oval, with exposed, nearly level spire and tilted 

 pirotoconeh. Jura to Recent. 



Hydatina Schumacher. Jura to Recent. Aplustrum. Schumacher ; Micromelo 

 Pilsbry. Recent. 



Family 5. Bullariidae Pilsbry (emend.). 



Shell oval or sub-globose, involute, smooth. Spire sunken and concealed. Aperture 

 long, rounded anteriorly ; outer lip sharp. Marine. Jura to Recent. 



Bullaria Raf. {Bulla Linn.) (Fig. 1064). Oval, inflated, with sunken spire and 

 perforated apex. Aperture rounded posteriorly and anteriorly. Jura (?) to Recent. 



