10 MEMOIR ON MOSASAURUS 



curved backward; fluted near the base on the inner face with smooth and fine 

 enamel, and have an expanded osseous support resembling that of Mosasaurus. 

 Several are figured in PL III. Figs. 1, 2, 3, 4, 5. I propose for this genus the 

 designation of Conosaurus,* and for the species the name of the discoverer, a 

 gentleman diligently engaged in developing the palaeontology of South Carolina, — 

 Conosaurus Boivmani. 



In the London Geological Journal, (No. I.,) Mr. Toulmin Smith has figured 

 teeth very similar to these from the Chalk of Lewes. He says, — " The teeth are 

 conical and much curved, perfectly smooth, uncompressed, and with no trenchant 

 edge. They are attached to conical and prominent osseous bases, which are shed 

 with the teeth, leaving very deep circular alveolar cavities, but no trace of a tooth 

 rising from below to replace the one which has fallen out." 



AMPHOEOSTEUS, Nov. Gen. 



Professor E. T. Brumby, of the South Carolina College, lately submitted to me 

 two large vertebrse of a Mosasauroid animal, from the Cretaceous deposits of Ala- 

 bama. They exceed in size any of those figured or described by Faujas, in the 

 Natural History of St. Peter's Mountain. 



The size of one (PL IH. Fig. 11) is, — 



Length, ........ 41 inches. 



Breadth at the middle of the centrum, . . . 4^ " 



Vertical thickness, ...... 2t " 



Longitudinal diameter of post, articular face, . . 5-y " 

 Short diameter, ....... 3i '' 



It is much compressed, (Fig. 12,) and the ellipse of the convex surface (Fig. 10) 

 is much longer than in Mosasaurus ; the centrum is more flattened, and the surface 

 of attachment of the lateral apophyses is much thinner (Fig. 12); the concave 

 articular face is much deeper, and the convexity of the opposite end greater, than 

 in any of the vertebrse of Mosasaurus which I have examined, and it projects more 

 over the body. Below the edge of the convex articulating face is a contraction, 

 almost amounting to a groove, which is not present in the vertebrse of Mosasaurus. 

 The other specimen is represented by Figs. 14, 15, 16, of PL III. It seems, there- 

 fore, probable that these vertebrse belonged to a huge animal of the Mosasauroid 

 group. 



In the measurement of the vertebrse of Mosasaurus Hoffmani, no one is repre- 

 sented as larger than two inches in length, and two and a half inches across the 

 articular face. This is about the size of the vertebrae from New Jersey, and of 

 those from Ashley Eiver, South Carolina. 



For this remarkable saurian the generic name of Amphorosteus "l* is appro- 



* From KWTOf, conus. 



f From the resemblance of the vertebrse, in outline, to an ancient dfjL<p6pa. 



