PELECYPODA 



479 



101, with a iiosterior myophoric crest for the adductor ; fixed valve conical or spiralj 

 Cardinal formula 010; ligament in a dcej) groove, almost internal, parivincular, 

 opisthodetic. Cretaceous. 



Gaprina d'Orb. {Gemmellaria Mun.-Chalm. ; Gornucaprina Fiitt.) (Figs. 771, 772). 



Fio. 771. 



Longitudinal section of 

 the lixed valve of Caprina 

 adversa, shovving cavities in 

 the inner .shell layer. 



Fig. 772. 



Cross-section 

 of the free valve 

 of Capritui mm- 

 inunis Gemmeh, 

 showing parallel 

 canals in the 

 middle layer. 



Fig. 773. 



Flagioptychus aguüloni d'Orb. Upper Cretaceous ; 

 Gosau, Austria. s/^j. 



Very inequivalve, attaclied by tlie apex of the coniform right valve. Left valve large, 

 spirally twisted ; inner layer of lower valve made up of concentric lamellae between 

 wliich cavities are sometimes left. The middle layer of the free valve traversed by 

 numerous simple, wide, parallel canals, extending from the margin to the apex; tooth 

 of the attached valve well developed, a series of depressions between the posterior 

 adductor scar and the margin. Cenomanian. The typical species, G. adversa d'Orb., 

 is of large size. 



Schiosia Böhm. Like Gaprina, but the fixed valve somewhat gyrate and the 

 canal syatem present in both valves. Cenomanian ; Upper Italy. 



Flagioptychus Math. {Sphaerocaprina Gemm. ; Orthoptychus Futt.) (Figs. 773, 



A B 



Flagioptychus aguüloni (d'Orb.) (P. paradoxus Math.). Upper Cretaceous (Hippurltes Liniestone); Le 

 Beausset, Var, France. A, Right. B, Left valve of the same individual, seen from within, 2/3. «, Anterior; 

 a' Posterior adductor scar ; l, Ligamentary groove ; c, Anterior tooth ; c'. Posterior tooth of left valve ; 

 d! Socket ; s, Buttress. . C, Section of the small valve near the margin, showing canals (y) of tlie middle layer. 

 Magnified. 



774). Right valve conical or twisted, attached ; left valve convex, with inciirved 



