4X0 J. P. J. Ravn. 



Oblong-oval, comparatively little oblique and rather strongly 

 arched. The umbo a little in front of the middle. The circumference 

 evenly rounded. The surface with fine, concentric lines of growth, 

 otherwise smooth. 



Height 18 mm, length 23 mm, thickness ca. 5 mm. 



The available specimens differ from Lindstrom's original examples 

 especially in that they are higher and more strongly arched. It is 

 possible, however, that these original examples were somewhat de- 

 formed by pressure. 



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

 Koldewey Island (1 spec). In a loose-lying stone at "4. SaMikning" 

 on the same island (1 spec). 



52. Cyprina Panderi Rouillier sp. ? 

 1847—48. Astarte Panderi Rouim.ikr, Etudes progr. Geol. Moscou. II. p. 418; PI. G. 



fig. 28. 



I am inclined to refer some few, incomplete shells to this species, 

 especially from the nature of the surface. 



The shell rather strongly arched, slightly triangular-circular, 

 comparatively little oblique. The umbo a little in front of the middle. 

 The surface with characteristic, sharp, canaliculated, concentric furrows 

 at regular distances from one another; further with very fine, con- 

 centric lines. 



Rouillieb states, that this species forms a connecting link with 

 the genera Astarte, Lucina and Cyprina, and that it is very nearly 

 related to C. Syssollae. To judge from the hinge, which he figures, 

 it seems most natural to refer it to the genus Cyprina, also because 

 it lacks the distinct, anterior pedal scar which is characteristic for 

 the genus Astarte. 



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

 Koldewey Island (3 spec). 



Russia: in the 2. Etage of the Moscow Jurassic 



53. Pleuromya peregrina d'Orbigny sp. 



1845. Panopaea peregrina d'Orbigny; Murchison, DE Verneuii. et Keyserung, Geo- 

 logic de la Russie d'Europe. II. p. 468: PI. 40. 

 figs. 10—12. 



1847. Panopaea peregrina d'Orb. : Rouili.ier, Etudes progr. Geol. Moscou. II. p. 406. 



1881—85. Pleuromya peregrina d'Orb.: Zittel, Handbuch der Palaontologie. II. 



fig. 179. 



The shell thin, rather strongly arched, rounded triangular; the an- 

 terior margin truncated, the posterior margin more curved, the ventral 

 margin slightly curved. The umbo somewhat in front of the middle, 

 but little prominent, bent strongly inward and somewhat forward. 



