| 
R 
Cope. 266 | Dee. 
in Edestosaurus dispar, is usually perfect in Liodon dyspelor. The 
pubes are the only elements united below, forming a weak support to the 
abdomen. The ilia are slender, not united with vertebral processes above, 
or without indications of such contact. The ischia are the most slender 
and directed backwards. 
Fourthly, in the hind limb. The femur of tL. crassartus has been 
described by the writer, and Professor Marsh asserts its existence in Lio- 
don, Clidastes and Edestosaurus. The present collection exhibits both 
femur, tibia and fibula of L. dyspelor, and these elements are now first 
described. The first mentioned is not larger, sometimes smaller than the 
humerus, and has a prominent trochanter, nearly connected with the 
head. The shaft is not curved, and the distal end is expanded. The 
tibia is a narrow bone expanded at both ends, the fibula is like that of 
Plesiosuurus, but wider, or partly discoid. It has been known to ni vtural- 
ists but not Sctovariued. Thus I figured it for Liodon taevis,* and Leidy 
figured it for an upper Missouri species.+} 
CLIDASTES, Cope. 
Proc. Acad. Nat. Sci., Phila. 1868, p. 238. Trans. Amer. Philos. Soe. 
1870, 211. 
Vertebree with the bt articulation. [Palatine bones flat and 
alate, the teeth not exposed at their bases unequally. This point has not 
been observed in the type species, C. iguanavus. ] 
CLIDASTES CINERIARUM, Cope. 
Proc. Amer. Philos. Soc., 1870, 583. 
Several individuals from different points near the Smoky Will 
eo 
Kansas. 
The largest specie 
8 
CLIDASTES VYMANU, Marsh 
Amer. Jour. Sci. Arts, June, 1871. 
From two individuals from the Smoky Hill River and its North F 
A small species. 
ork, 
CLIDASTES PuMILUS, Marsh, l. ¢. 
From one individual from the Smoky Hill River. 
The smallest known Mosasauroid. 
EDESTOSAURUS, Marsh 
Amer. Jour. Sci. Arts, 1871, June. 
Vertebre with the zygosphen articulation; palatine bones narrow, 
partly vertical, the bases of the pterygoid teeth exposed on one side, or 
pleurodont. (Tt 3 is uncertain whether the type of Clidastes presents this 
structure or not.) 
EDESTOSAURUS TORTOR, Cope, Sp. NOV. 
Vertebre of the cervical and anterior dorsal regions with round articu- 
lar faces, not emarginate for the spinal cord. The bodies are elongate 
* Trans. Amer. Philos, Soc. 1869, 205. t (Cretaceous Reptiles, ) U.S. Tab. viii. fig. 10. 
etic, 
SR cnyr 
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