First Expedition to Kansas Chalk 51 



the ocean-bed that even the gases formed in his 

 stomach could not lift his body to the surface. A 

 second specimen was sent to the British Museum of 

 Natural History, in London; a third to Munich, 

 Bavaria, and a fourth to the Roemer Museum, in 

 Hildesheim, Germany. 



This last specimen is the best I ever took from the 

 Kansas chalk until 1907. It is twenty-five feet long. 

 Unfortunately, the head was all washed away, with 

 the exception of the mandibles and a few bones of 

 the skull. The most remarkable feature of this 

 specimen was the presence, for the first time in my 

 experience, of the complete cartilaginous breast- 

 bone with the cartilaginous ribs, which are very 

 rare. They were described for the first time from 

 the noble Bourne specimen, by Dr. H. F. Osborn, of 

 the American Museum. 



This mosasaur, Platecarpus, is the most common 

 species known, and is almost as large as the big 

 Tylosaurus. It differs from the latter, however, in 

 the shape of the short, strong paddles and the blunt 

 rostrum. The skull in the illustration (Fig. 10) is 

 that of a very fine specimen, one of my discoveries, 

 which was mounted by Mr. Bunker, of the natural 

 history department in the Kansas State University. 

 I have never seen a more complete skull, or one that 

 shows the height so well, in any specimen, unless it 

 is the little Clidastes velox, in the Kansas University 



