82 CRETACEOUS GROUP 



From the calcareous strata of New Jersey, where it is 

 of frequent occurrence. 



This shell has a strong resemblance to Planorbis ; and 

 Mr. Sowerby mentions that he found shells of a similar 

 character in the English Green sand, (Min. Coch. p. 89, 

 92.) The American shell appears to belong to the ge- 

 nus Vermetus as revised by Mr. Sowerby. 



Tellina. 



Finely preserved casts of a delicate Tellina, upwards 

 of an inch in length, occur in the arenaceous beds of New 

 Jersey. 



LUNULITES. 



Casts of a Lunulite, about a fourth of an inch in dia- 

 meter, have been observed with the preceding fossil. 



It will be observed that I have used the genus Ammo- 

 nites in its unrestricted acceptation : the A. Delawaren- 

 sis and A. vespertinus are true Ammonites, while all the 

 other species of this synopsis might be associated with the 

 genus Orbitulites of Lamarck. 



