Fig. 381. Terebratulina atlantica. 

 (After Whitfield.) 



BRA CHI OP OD A — TEL TREMA TA. 305 



incomplete; dental plates wanting. Brachial valve with small car- 

 dinal process; hinge plate and median septum wanting; socket 

 walls prominent, supporting a short Dielasma-Yxke. loop with the 

 crural spines typically united into a transverse band or jugum. 

 Surface finely radiate. Jurassic-Recent. 



302. T. atlantica (Morton). (Fig. 381.) Cretacic. 

 Ovate. Valves unequally convex. Length about ^ inch ; 



width y 2 inch. Pedicle valve with large foramen; beak not in- 

 curved. Both valves covered 

 with numerous bifurcating 

 striae. 



Upper Cretacic (Manasquan) 

 Staten Island and New Jersey. 



XCIV. Tropidoleptus Hall. 

 Form strophomenoid. Hinge 

 line straight; area well devel- 

 oped. Pedicle valve convex 

 with two broad divergent teeth and open, subcircular delthyrium. 

 Brachial valve concave or flat with large cardinal process bilobed 

 at summit. Teeth and dental sockets corrugated on their outer 

 surfaces. Shell substance highly punctate. Loop of descending 

 lamellae joined to median septum. Devonic. 



303. T. carinatus (Conrad). (Fig. 382.) Devonic. 

 Plications simple, rounded, wider than the interspaces. Central 



plication of pedicle valve broader and higher than the rest. Con- 

 centric striae fine with occasional coarser imbricating lamellae. 



Marcellus and' Hamilton of New York, Pennsylvania, Ohio. 

 Kentucky, Indiana, Illinois. Also foreign. 



XCV. Kingena Davidson. 

 Subovate, biconvex, inequivalved ; terebratuloid in outline, con- 

 vexity and foramen. In brachial valve a cup-like hollow between 

 the sockets gives rise to a median septum extending about half the 

 length of the valve. Loop more complicated than in Terebratula, 

 Shell structure punctate. Comanchic. 



304. K. wacoensis (Roemer). Comanchic. 

 Pentagonal, frontal margin straight. Both valves very convex. 



Pedicle valve with beak greatly incurved and with a distinct car- 



