On Jurassic and Cretaceous fossils from North-East Greenland. 457 



Some specimens of an Ancella seem — to judge especially from 

 their characteristic sculpture — to be nearly related to .4. reticulata. 

 A cast with a small portion of the shell preserved forms the basis 

 of the following description. 



Circumference short-oval. Left valve strongly arched; beak 

 strongly bent backwards; anterior margin forming an even curve 

 with the ventral margin; posterior margin long and straight, meeting 

 the very convex ventral margin in a sharp bend. Right valve only 

 slightly arched, most strongly in the direction from the front to the 

 hind margin. Both valves covered with very prominent, concentric 

 lines, crossed by equally strong radial lines; no distinct knots at the 

 points of crossing. 



Left valve: length ca. 21 mm, breadth 19 mm and thickness 7 mm ; 

 angle at the beak ca. 80°. 



In the Riksmuseum of Stockholm I have compared the available 

 specimens with Luxdgrkx's originals, from which they differ in two 

 points, their length is not so great and the left valves are consid- 

 erably more arched. As Lundghen noted, his original specimens 

 were compressed, so that the disagreement in form is possibly only 

 apparent. 



A. reticulata is stated by Lundgren to have been found on Spitz- 

 bergen along with A. radiata and A. spitzberaeusis (= A. Bronni ?). 



Distribution. North-East Greenland: in boulders on the south 

 side of Vesterdalen at Danmarks Havn (4 spec, 2 of them connected). 

 In boulders at Danmarks Havn ((5 spec). 



13. Aucella mosquensis v. Buch sp. (non KEYSERLING, non Lahusen). 



PI. XXXII, fig. 6. 



1844. Aoicula mosquensis v. Buch, Neue Verst. aus Moskau, p. 537; PL (>, fig. 1. 

 1846. Aucella Pallasii Kkyserung, Petschora-Land, p. '299; PI. 16, figs. 1—6. 

 1848. Buchia — ; Rouillier, Etudes progr. Geol. Moscou, II, p. 272; 



PI. D (Bull. Soc. naturalistes Moscou 1846), fig. 3. 

 1866. Aucella mosquensis v. Buch var. ; Eindstrom, Trias- och Juraforsteningar fran 



Spetsbergen, p. 14; PI. 3, fig. 3. 

 1888. — Pallasii Keys.; Lahusen, Ueber die russischen Aucellen, p. 34; PI. 1, 



figs. 12- 20. 

 1904. — — — ; Madsen, Jurassic Fossils from East-Greenland, p. 178; 



PI. 6, fig. 7. 

 1907. — mosquensis Buch (non Keys., non Eahus.); Pavlovv, Enchaiiiement etc., 



p. 22; PL 2, figs. 5-8. 



Of this species only the casts of a couple of left valves were 

 found. 



The left valve with ovoid circumference, somewhat strongly 

 arched, very oblique. The umbo inclined backward and at the same 

 time far over the right valve; its outermost point bent a little for- 



