104 PROCEEDINGS OF THE ACADEMY OP 



Among the specimens from the Cretaceous exhibited were por- 

 tions of a slveleton with the caudal series complete of a new species 

 of Clidasles, about the size of Clidastes propylhon. The anterior 

 caudals were elevated, and the diapophyses extended back to 

 about the twenty-fourth vertebra witli chevrons. The tail was 

 extremely attenuated, as there are in the series eighty-one vertebrae 

 with chevrons, the terminal ones being less than one-twelfth of an 

 inch in diameter. The muzzle in this species is less pointed than 

 in G. j)ropijtJion. The remains were found in the Cretaceous of 

 Kansas, and the species was named Clidastes Wijmani. 



A second and very diminutive species of the same genus was 

 represented by portions of the skull and teeth, with the quadrates, 

 and several cervical vertebrae. The species was consideral)ly 

 smaller than C. propytlion, and differed essentially from that 

 species in several respects, especially in the quadrate, which had 

 the postero-superior process terminated by a short compressed 

 hook. The teeth were smooth and nearly round at the base. 

 This species, which was also from the Gray Shale of Kansas, is 

 the smallest known mosasauroid, and Avas hence named Clidastes 

 pumilus. Another new Cretaceous reptile was indicated by two 

 teeth, which were found together in the middle marl bed at Bir- 

 mingham, New Jersey. They apparently belonged to a Croco- 

 dilian, probably allied to Huposaurus. One of the teeth, apparently 

 from the anterior part of the jaw, is long, pointed, nearly round, 

 and covered with strong angular but smooth ridges, except just 

 at the ai)ex, where the}' disappear. The posterior cutting edge 

 is sharp and prominent, and extends the entire length of the 

 crown. The anterior edge is onl}' distinct a short distance near 

 the apex. The second tooth has the crown short and compressed, 

 with irregular ridges, and resembles somewhat the posterior teeth 

 of Hyposawiis. These specimens indicate a species considerably 

 larger than H. Rogersii, which, until its generic characters are more 

 fully determined, may be called Hyposaurus ferox. 



Among the other reptilian remains exhibited b}'^ Professor 

 Marsh were several new species of Crocodilians from the Tertiary 

 of Wyoming. One of these, which was named Crocodilus ziphodon^ 

 was remarkable in having smooth compressed teeth, with serrated 

 edges, resembling the teeth of some of the carnivorous Dinosaurs. 

 This animal, which was of moderate size, appears to have been 

 covered witli articular scutes. The quadrate was subtriangular in 

 transverse outline at its distal end. Another small species, also with 

 articulated scutes, was indicated by the more important parts of 

 the skeleton. It liad verj^ slender jaws, and smooth, nearly round 

 teeth. The quadrate was unusually flat at its distal end, and had 

 a broad longitudinal elevation on its lower surface. The hj'po- 

 l^hysis was simple, elongate, and compressed. The species was 

 named Crocodilus liodon. A third new species was apparently 

 indicated by a nearly complete skeleton, and parts of several 



[July 4, 



