REronT ON THE GEOLOGY OF NORTH AMERICA. Gl 



United States army, now at Fort Gibson, has obtained speci- 

 mens for my use, among which I readily identify the Gryphaa 

 Vomer, Exogyra costata, &c." 



For the sake of exhibiting more fully the conditions of the 

 comparison between the formations of the superior secondary, 

 or cretaceous group of North America, and the equivalent group 

 in Europe, I shall present the following summary of the or- 

 ganic remains hitherto discovered in New Jersey, Delaware, 

 and Alabama. 



Sauria. 

 Mosasaurus. — Thought to be identical with the Mosasaurus of 



Europe. New Jersey. {Morton.) 

 Geosaiirus. — Teeth and part of a jaw. New Jersey. {Defeat/.) 

 Crocodile. — Teeth and other portions, indicating three species, 



from the marl region. New Jersey. 

 Saurodon. — {Hays.) Portions of a jaw of an extinct animal, 

 the relations of which are not very clearly known. It is 

 thought to be analogous to the Saurians. (See American 

 Philosophical Transactiotis.) 

 Great Sauriati of Uonjleur. ? — I have recently described two 

 vertebrae from Jersey, and another from Alabama, which I 

 regard as either identical with, or very closely allied to, bones 

 figured by Cuvier from Honfleur, which he considers to ap- 

 proach nearer to the Plesiosaurus than to any other genus. 

 (See Journ. of the Acad. Nat. Sci. of Philadelphia.) 



Testudo. 

 Several bones from the marl deposit in New Jersey. {Morton.) 



Pisces. 

 Squalus. — Teeth and vertebrae of several species of shark are 



abundant in New Jersey and Alabama. {Morton.) 

 Sphyrcsna. — Some remains of this curious genus of fishes 

 occur in the blue marl of New Jersey. {Morton.) 



AvES. 



A solitary tibia of a bird of the genus Scolopax has been found 

 in the green marl in New Jersey. {Morton.) 



Testacea, &c. 



The whole number of Testacea, Echinodermata, and Zo- 

 ophytes described by Dr. Morton in his Synopsis of the Organic 

 Remains of the Cretaceous Group of the United States, is 108 

 species. Of these, two belong to genera which are new, while 

 one species only, the Pecten quinquecostatus, is thought to be 

 common to the strata of both America and Europe. 



This latter fact is certainly not a little remarkable, as it goes 



