458 



MOLLUSGA 



SUB-KINGDOM VI 



Callonema, Hall (Isonema, Meek and Worth). Turreted, oval to globose ; whorls 

 covered with lamellate transverse ribs ; aperture circular. Silurian and Devonian. 



Scoliostoma, Braun. Devonian. Chilocyclus, Bronn (Cochlearia, 

 Braun). Trias. 



Scalaria, Lam. (Scala, Klein ; Cirsotrema, Morch.), (Fig. 872). 

 Turreted; whorls strongly arched, with transverse ribs, and often 

 also spirally striated. Aperture round, outer lip sometimes thickened. 

 Trias to Recent. 



Family 2. Solariidae. Chenu. 



Shell depressed conical, deeply and broadly umbilicate, without 

 nacreous layer. Whorls angular; operculum horny or calcareous, 

 spiral. Embryonal spire 

 heterostrophic. Marine. 

 FIG 872 Cretaceous to Recent. 



Scalaria lamellosa, mi ^nTnrt'irlnf PY 



Brocchi. Miocene; 

 Baden, near Vienna, hibit some resemblance to 



the Euomphalidae, from 

 which they are distinguished principally 

 by the heterostrophic nucleus. 



Solarium, Lam. (Figs. 873, 874). 

 Aperture quadrilateral ; operculum horny ; 

 umbilical angle notched or sharp. Jura 

 to Recent. A number of Mesozoic forms confused with this genus probably belong to 

 Euomphalus. 



Torinia, Gray. Tertiary and Recent. Bifrontia, Desh. (Omalaxis, Desh.). Eocene. 



FIG. 873. 

 Solarium simplex, 



Miocene ; 

 Niederleis, Moravia. 



FIG. 874. 



Solarium Leymeriei, Ryckholt. 



(Uppe 

 Tournay, Belgi 



Superfamily 3. TAENIOGLOSSA. Bouvier. 



Teeth of the radula seven in each transverse row. Mainly holostomate forms, but 

 some genera have deeply notched apertures, as in the higher divisions. 



Family 1. Purpurinidae. Zittel. 



Thick-shelled, oval, with platform-like spire, and without 

 <iyer. Whorls flattened beneath the suture and 

 angular, the angles often beset with nodes. Body whorl 

 large ; aperture oval, with anterior emargination, and 

 discontinuous peristome. Operculum unknown. Ordo- 

 vician to Cretaceous. 



Scalites, Conrad. Spire short and acuminate ; whorls 

 flattened superiorly and bounded by a sharp angle at the 

 suture. Body whorl very large, smooth ; aperture faintly 

 notched. Ordovician (Chazy) ; according to Laube, also 

 Triassic. 



FlG 875 . Trachydomia, Meek and Worth (Trachynerita, Kittl) ; 



Purpuroideanoduiata, Young and Pseudoscalites, Kittl ; Tretospira, Koken. Trias. Brach- 

 Bird sp. Great Oolite ; Minchin- trema, Morris and Lvc. ; Tomocheilus, Gemm. Jura. 



hampton, England. ' . -,,,^11 , -,-, , i 



Purpunna, d Om. Elongate-oval. Whorls angular 



superiorly, spirally ribbed, with transverse folds or costae, highly ornamented, often 

 with umbilical fissure. Aperture oval, anteriorly notched. Rhaetic and Jura. 



Purpuroidea, Lycett (Fig. 875). Spire with successive steps or platforms, the 



