On .Jurassic and Cretaceous fossils from North-East Greenland. 477 



should possibly he referred. They are more or less complete easts. 

 with here and there the inner layer of the shell preserved. 



The shell to some extent circular, somewhat elongated in front. 

 The umbo almost median, somewhat projecting. The posterior part 

 of the circumference of the shell semicircular, hut with a pair of 

 faint concavities. The margin in front of the umbo strongly concave. 

 On the hindmost portion of the shell a deepened part, extending 

 from the umbo down along the posterior margin ; this depression 

 well-marked on the cast. The surface probably with fine, concentric 

 striae and with fine radial lines; the latter also apparent on the 

 cast. — The hinge and muscular impressions not apparent. 



Height ca. 47 mm, length ca. ;il mm and thickness (cast of a 

 double-valved spec.) 19 mm. The largest specimen is ca. 60 mm 

 high. 



A small, badly preserved specimen from "4. Saenkning" perhaps 

 belongs to the same species, but seems to be more strongly arched 

 than the other Greenland specimens. 



Distribution. North-East Greenland: "Kloft II" on Store 

 Koldewey Island (3 spec, 2 of them double-valved). ? At "4. Saenkning" 

 in loose-lying stone (1 spec). 



Germany: in Kimmeridgian at numerous localities in North 

 Germany. 



France: in Kimmeridgian-Portland. 



47. Protocardia sp. 



I have not been able with certainty to refer some specimens of 

 a Protocardia to any species known to me. 



The shell rather strongly inflated, rounded-trapezoidal, with 

 unequal sides; the umbo inclined somewhat forwards. The anterior 

 margin rounded and passing evenly into the rather slightly rounded 

 ventral margin. The posterior margin somewhat elongated downwards 

 and grading fairly evenly into the ventral margin. The whole of 

 the surface, with exception of the hindmost part, smooth, showing 

 only fine, concentric lines of growth. In the neighbourhood of the 

 posterior margin a strongly rounded radial ridge; the shell behind 

 this sloping very steeply down towards the posterior and cardinal 

 margins. Behind the ridge ca. 8 rather faint radial ribs, and in front 

 of the ridge a few still fainter. The part of the margin touched by 

 the ribs crenulated, the remainder smooth. 



A single valve is 19 mm high, IS mm broad and ca. (i mm 

 thick. 



Possibly the specimens described (3 in number), which were 

 found in "Kloft I" on Store Koldewey Island, may he referred to 



