SUB-ORDER B 



PLATYPODA 



457 





Pustularia, Koken. Turreted, with groove-like sutures. Whorls flat, with three 

 or more spiral rows of nodes. Trias. 



Catosira, Koken. Whorls flat, with transverse ridges. Aperture canaliculate; 

 base with spiral grooves. Trias and Jura. 



Diastoma, Desh. (Fig. 866). Like the last, 

 but aperture separated from the body whorl. 

 Whorls with transverse folds and spiral striae. 

 Cretaceous and Tertiary. 



Mathilda, Semper (Promathilda, Andreae). 

 Turreted ; whorls transversely and spirally 

 striated or ribbed. Aperture with canal. 

 Nucleus heterostrophic. Jura to Recent. 



Keilostoma, Desh. (Paryphostoma, Bayan), 

 (Fig. 867). Turreted, spirally striated. Outer 

 lip with externally thickened margin. Eocene. 



Turbonilla, Risso (Chemnitzia, p.p. d'Orb.), 

 (Fig. 868). Small, turreted, with heterostrophic 

 nucleus. Whorls transversely ribbed or smooth. 

 Inner lip straight, or occasionally with folds. 

 Tertiary and Recent. 



Odontostoma, Fleming (Fig. 869); Pyrami- n^?**** 

 della, Lamarck (Fig. 870). Cretaceous to Recent. 

 Syrnola, Adams ; Eulimella, Fischer. Tertiary and Recent. 

 Trias and Jura. 



The genera Subulites, Conrad (I Polyphemopsis, Portlock), from the Cambrian to 

 Carboniferous ; Fusispira, Hall, Ordovician ; and Soleniscus, Meek and Worthen, Car- 



FIG. 867. 



Fia. 800. 



Lam. sp. 



eostellata, 

 Calcaire 



turri- 

 culu, IJruj:. sj>. 

 (Mi l>i a ; iiiiiriiiii'it''. 

 Lam.) ; Calcaire 

 Grossier ; Grignon, 

 near Paris. 



Palaeoniso, Gemm. 



FIG. 808. 



Turbonilla rufa, 

 Phil. Crag; Sntton, 

 England. 



FIG. 869. 

 Odontostoma pli- 

 cata, Montf. sp. 

 Upper Oligocene ; 

 Nieder-Kaufnngen, 

 near Cassel. 



Pyramidella pli- 

 cosa, Bronn. Mio- 

 cene ; Niederleis, 

 Moravia. 



Euchrysaiis fusi- 

 formis, Mvinst. 

 sp. Trias ; St. 

 Cassian. Tyrol. 



boniferous, are characterised by narrow, anteriorly elongated and canaliculate aper- 

 tures. They probably form a separate family, in which also should be placed the 

 Triassic Euclirysalis, Laube (Fig. 871). 



Superfamily 2. PTENOGLOSSA. Gray. 



Teeth of the radula subulate, numerous, and similar in each transverse row. 



Family 1. Scalariidae. Broderip. 



Shell turreted, usually narrowly umbilicate. WTiorls convex, transversely ribbed or 

 striated. Aperture round, with entire peristome. Operculum horny, paucispiral. 

 Marine. Silurian to Recent. 



Holopella, M'Coy (Aclisina, de Kon.). Slender, turreted ; whorls with fine trans- 

 verse striae, sometimes cancellated. Silurian to Carboniferous. 



