40 KANSAS UNIVERSrrV (^)UARTERLY. 



length of 140 millimeters. There are twelve vertebrae that may be 

 called thoracic. The ribs of this region measure respectively: 

 first rib, about 350 mm.; second, 440 mm.; third, 440 mm.; 

 eleventh, 410 mm.: twelfth, 160 mm. There are ten dorso-lumbar 

 ribs to the beginning of the pygal region, the whole number of the 

 precaudal vertebrae being twenty-nine. 1 am very much inclined 

 to believe that the different individuals of any species may vary 

 some\vh.at in the number of dorso-lumbar and post-dorsal vertebrae. 

 The posterior thoracic ribs are more slender and less stout than the 

 anterior ones. The costal cartilages, which are so frequently 

 found -in all the genera, are flattened and pitted, of a less dense 

 and more granular structure than the true bones. They lie in this 

 specimen parallel with each other in several rows. 



In the present specimen there is a well ossified sternum, broadly 

 crescentic in shape, with the posterior border concave, and the 

 deep groves for the reception of the coracoids placed widely apart 

 and at an obtuse angle with each other. From the fact that one 

 of the coracoids shows much exostosial growth, united thereby- 

 with the scapula, I am inclined to believe that the ossification of 

 the sternum may be due largely to pathological causes, and that, 

 normally, the sternum in this genus, as in others, is composed of 

 calcified cartilage, as are the costal ribs. 



On the under side of the sternum and partially ossified with it, 

 projecting in front as a broadly spatulate, thin process, is the 

 interclavicle. The posterior portion is slender and not very long; 

 at its anterior, truncate extremity, there are two oval facets, as 

 though for articulation with bones. 



The front paddle resembles in its position very much that of 

 /'. iiirriciis given by me in plate xliv, vol. iv, Univ. Geol. Surv. 

 Kans., except that every bone is in its normal position. The edge 

 of the fleshy portion, which is clearly outlined, follows the sweep 

 of the radial side of the fingers about an inch distant. Between 

 the fourth and fifth finger the edge of the membrane is concave to 

 the tip of the fifth finger. Thence the margin extends broadly 

 inward to the side of the body. The paddle evidently was not 

 pedunculated, but was broadly connected with the body. The 

 outline of the body in the abdominal region was clearly traced in 

 collecting the specimen; it is about as it is represented in the 

 restoration of Clidastes. 



Not the least interesting information furnished by this specimen 

 is that concerning the food of the animal. Quantities of its remains 

 were discovered in the abdominal region, matted together and 



