On Jurassic and Cretaceous fossils from North-East Greenland. 489 



down from "Trækpasset" on Store Koldewey Island at a height оГ 

 50 m above the sea. 



The shell has i)een somewhat involute with inflated whorls. 

 The breadth of the whorl Гаг exceeds its height; the external outline 

 from edge to edge of the umbilicus is very approximately a semicircle; 

 the older whorls have been relatively higher. Edge of the umbilicus 

 not sharply marked. The ribs strong, especially in the neighbourhood 

 of the edge of the umbilicus; a few divide into two a little below 

 the middle of the side; at other places a new rib is inserted. In 

 the cases of dichotomy the two ribs do not unite again on the other 

 side, but join on to the rib respectively before and behind. From the 

 umbilicus to the umbilical edge the ribs are bent somewhat backwards; 

 then they bend forwards and on the external part form a distinct arch 

 bent forwards; they course over the external part without interruption. 



Height of the whorl 20 mm, breadth 29 mm. 



The available fragment has a no slight resemblance to an Ammo- 

 nite, which Lahusen (1. c, PI. 4, lig. 11) ligures under the name of 

 Cardioceras carinalum P^ichw., but the material is too incomplete for 

 a certain determination. 



(59. Cosmoceras boréale n. sp. 

 PI. XXXVI, figs. 5 and (J. 



The shell with rather small umbilicus and with inflated whorls; 

 the older whorls lower and thicker than the younger. The slope 

 down towards the umbilicus short, but steep. The thickness of the 

 whorl increasing from the edge of the umbilicus; its greatest thickness 

 at about 1 3rd of the distance from the umbilical edge to the ex- 

 ternal side; here a spiral row of small, pointed nodes. The region 

 from this up to the external side convex. The external side itself 

 with a distinct furrow. The sides covered 

 with rather fine, sharp ribs, beginning right 

 down at the umbilicus and directed some- 

 what forwards. No marked nodes on the 

 umbilical edge, but here the ribs are spe- 

 cially strong. Dichotomy of all the ribs at 



the lowermost row of nodes ; at the same щ^ 4. Sulure-llne of Cosmoceras 



height sometimes insertion of new ribs. '""''"'^' "• "p- ""-^'t °^' "^<^ 



*-" _ whorl 8 mm. 



Never junction of ribs at the external edges; 



on the other hand, the ribs here as a rule somewhat swollen, but 

 without any true formation of nodes. No appreciable weakening of 

 the ribs in the external furrow. — The suture-line dentated compara- 

 tively coarsely; the external lobe rather narrow; the first lateral lobe 

 with one point, of the same length as the external lobe. 



