TELOTREMATA 



325 



(Ynra very long, ventrally curved. Median septum of dorsal valve faint. 

 I ura ; Sicily ami tin- Alps. 



i., Zittel. Small plicate shells with a high umbo and a straight 



Fie;. 543. 



A, rJn/itchonclla loxia, Fisch. Upper Jura ; Moscow, a, 7), Profile 

 and dorsal view, l/i ; c, Cast ; d, Anterior view. B, R. quadri'plicata, 

 Quenst. Middle Jura ; Boptingen, Wiirtemberg. 



A, 



Brocchi. Upper Cretaceous ; 

 Villedieu, Touraine. 1/1- B, R. 

 lacunota, Schloth. sp. Upper 

 Jura ; Engelhardsberg, Francdhia. 

 Interior of dorsal valve. 



hinge-line. Delthyrium large, with linear deltidial plates. Dorsal valve 

 with a high median septum extending to the ventral valve. Alpine Trias. 



Peregrinella, Oehlert. Large, strongly plicate Rliynclwnellae without fold 

 or sinus. Cardinal area well 

 developed. Cretaceous; 

 Europe. 



Hemithyris, d'Orb. (Fig. 

 545). Smooth or faintly 

 plicate Khynchonellae with a 

 high ventral beak and open 

 delthyrium. No dental 

 plates. Recent. 



Fio. 545. 



n i T\ 11 t> ]I ' '""'"' '"'''"' ]'<t f '"'<'" ,Lam. sp. 



Fnelem, Dall. Resem- Mediterranean. Vi- 



Schloth. sp. Middle 

 Jura; AaeroaoK. Upper 

 Palatinate. 



bling Fjfmithyris, but with a 



small dorsal spondylium. Recent ; American Pacific. 



Acanthothyris, d'Orb. (Fig. 546). Like the last, but with well-developed 

 dental plates, and the exterior surface covered with spines. Jura to Recent ; 

 Europe and Japanese Province. 



( 'ri//>fn/H>ra, Jeffreys (Atretia, Jeffreys ; Neatretia, Oehlert). Small smooth 

 shells with an acute and prominent open ventral beak. Dental plates and 

 a high, mesially situated, dorsal septum present. Recent. 



Cydorhina, Hall and Clarke. Devonian ; North America. 



Superfamily 2. TEREBRATULACEA. Waagen. 



Derived Telotremata with the brachia supported ly calcareous, primitive, or meta- 

 morphosed loops. Devonian to Recent. 



