On Jurassic and Cretaceous fossils from North-Kast Greenland. 455 



The valve almost symmetrical and somewhat arched. Its surface 

 covered with numerous radial ribs, which seem to vary somewhat in 

 size and have possibly home small, short spines or teeth. 



In other boulders from Vesterdalen are some fragments of valves, 

 of which only the inner side can he seen; these have also had ribs, 

 alternately finer and coarser. How far these valves belong to the 

 same species as the above, cannot be determined. 



9. Aucella kirghisensis SokOLOW. 



PI. XXXII, fig. 2. 



1903. Aucella kirghisensis Sokoi.ow, Aucellen aus Ost-Russland, p. 374; PI, 14, figs. l-.">. 



1907. — — — ; Pavlow, Enchainement etc., p. IS; PI. 2, figs. 



18-19. 



1908. — — — ; Sokolow, Aucellen voin Timan und von Spitz- 



bergen, p. 10; PI. 1, figs. 12-14. 



Some fairly perfect casts agree exceedingly well with the above- 

 cited descriptions and figures. 



The form of the shell oblong-oval, somewhat oblique. The left 

 valve strongly inflated, right valve somewhat less so. The beak 

 comparatively little prominent. Ear indistinct. Surface of the casts 

 covered with little prominent, concentric lines of growth and still 

 more indistinct radial ribs. 



The length : of the left valve figured is ca. 22 mm, its breadth 

 ca. 1(5 mm and its thickness 6 mm; the angle at the beak is 

 ca. 95°. 



Distribution. North-Kast Greenland: "Kloft I" on Store Kol- 

 diwey Island (5 spec). 



Russia: in deposits with Caidiocerus alternam. 



10. Aucella Bronni Lahusen. 

 PI. XXXII, fig. 5. 



1888. Aucella Bronni Rorn.L. ; Lahuskx, Ueber die russischen Aucellen, p. 32: PI. I, 



figs. 1—7. 

 1901. — — — ; Pompeckj, Aucellen im Frankischen Jura, p. 24; 



PI. 4, fig. 4. 

 1907. — — Lahus.; Pavlow, Enchainement etc., p. 14; PI. 1, fig. 31. 



The left valve oblong-oval, very oblique, somewhat strongly 

 arched, flatter towards the posterior margin. The beak comparatively 

 small and little prominent, curved inwards. The anterior margin and 

 ventral margin forming a flat curve; the posterior margin slightly 

 concave, almost straight. Surface of the cast covered with numerous, 

 distinct, concentric folds and with numerous, fine, less distinct radial 



1 The method used in measuring this and the following Aucella species is that 

 of Pavlow (1. C, p. 10— 11). 



33* 



