40 CRETACEOUS GROUP 



monite. If it be not identical with the preceding species, I 

 propose the name of A. petechialis. 



Variety C. PI. xix. fig. 4. 



Elongated like a scaphite, the whorls being more distinct, 

 and less in diameter, than in any one of the preceding varieties. 



At first I pronounced it a Scaphite, but it appears to 

 glide by degrees into the A. Conradi. If it be not the 

 same, it may be called A. navicularis. That it is not 

 a Scaphite, but an accidentally elongated Ammonite, I 

 am entirely certain. I have one fragment of A. Conradi, 

 which must have been upwards of four inches in dia- 

 meter. 



6. A. syrtalis. (S. G. M.) PLcxiv) fig. iv. 



Specific Character. Shell much compressed, but widening 

 rapidly towards the aperture; two series of nodes, one on the 

 umbilical margin, the other near the periphery ; nodes but 

 little elevated, except on the umbilical margin, near the aper- 

 ture, where they are profoundly elevated : periphery with two 

 series of pyramidal nodules, giving it a dentated appearance ; 

 septae distant, sigmoidal. Greatest diameter about three inches. 

 From the older cretaceous deposits of Greene county, 

 Alabama. 



7. A. vespertinus. (S. G. M.) PI. xvii. fig. i. 



Specific Character. Volutions uncertain; each whorl fur- 

 nished with profoundly elevated transverse ridges, with three 

 slight nodes on each ; that on the margin most prominent. 



Length of the fragment 13J inches. 



My friend Dr. Z. Pitcher, of the United States' army, 

 has presented me with several large fragments of this Am- 

 monite, from the plains of Kiamesha, in Arkansaw ; where 



