On Jurassic and Cretaceous fossils from North-East Greenland. 4f>9 



south side of Vesterdalen at Dan marks Havn (3 left valves and (?) 

 1 right valve). 



Russia: Alternans deposits — Lower Portland. 



Mexico:? 



1"). Aucella crassicollis KEYSERLING. 

 PI. XXXII, fig. 8. 



184(i. Aucella crassicollis Kkyseri.ing, Petschora-Land, p. 300; PI. 10, figs. 9 — 12. 

 1874. — concentrica var. rugosa Keys.; Toui.a (pars), Kuhn-Insel, p. 503; PI. 2, 



fig. 3. 

 1888. — crassicollis Keys.; Lahusen, Ueber die russischen Aucellen, p. 42; PI. 5, 



figs. 9-13. 

 1895. — — ; Stanton, Knoxville beds, p. 45; PI. 5, fig. 8 and PI. (i, 



figs. 3—5. 

 1907. — — ; Pavlow, Enchainement etc., p. 02; PI. 5, fig. 10. 



Lett valve almost equilateral , usually however obliquely triangular, 

 very high and strongly inflated, from about the middle narrowing 

 very rapidly up towards the umbo; the uppermost half of the valve 

 thus narrow and elongated; beak inclined somewhat forwards and 

 strongly inwards. On the surface of the cast sometimes a single, 

 very deep, concentric furrow; further, rather faint traces of concentric 

 folds. — Along with the left valves some fragments of fairly Hat, 

 almost completely smooth right valves were found, which probably 

 also belong to this species. 



None of the specimens are so complete, that measurements can 

 he given. 



Distribution. North-East Greenland: in reddish brown lime- 

 stone in Aucellabjerget on Store Koldewey Island along with A. piri- 

 formis (many spec). — East Greenland: Kuhn Island (collected 

 by the 2nd German North Pole Expedition). 



Russia: in deposits belonging to the zone with Polijptijchites 

 polyptychic. 



America: in Knoxville Reds in British Columbia and California. 



16. Aucella sp. 

 PI. XXXIII, fig. 1. 



In a gray limestone in Aucellabjerget on Store Koldewey Island 

 was found a single left valve of an Aucella, which does not seem 

 to be referable to any of the species mentioned in this paper. 

 It is elongated, fairly equilateral and evenly arched; the beak is in- 

 clined slightly forward; angle at the beak ca. 77°. As the specimen 

 is not complete and there is only this one example, I do not venture 

 to refer it to any of the above-described species; it belongs in any 

 case, however, to the Kegserlingi-gcoup. 



