THE SERPENTLIKE SEA SAURIAN S. 217 



ful predaeeous sea serpent. The genus was founded by Cope in 

 1869; it has a wide distribution, and seven or eight species belong 

 to it. 



Tylosaurus proriger (Cope) is the third of Williston's type 

 Kansas specimens perfected in restoration. It is considered the most 

 specialized of the mosasaurs. The skeleton in hand is twenty-three 

 feet in length, and shows a wholly cartilaginous carpus and tarsus, 

 more elongated digits, and a greater number of phalanges than pos- 

 sessed by any other genus, the result of long aquatic habits. The 

 hind paddles are the largest, and the fifth digit has undergone but 

 little reduction, indicating characters of a very primitive rank. The 

 vertebrae are more flexible than in otlier genera, but they are rela- 

 tively smaller and not at all strong. The skull is more elongated 

 anteriorly. In the same genus was a much larger species, T. dyspelor 

 (Cope), which was one of the most formidable of the mosasaurs. An- 

 other perfected sea serpent of terrible powers was Mosasaurus Jior- 

 ridus (Williston), which had a ram nose, and evidently battered its 

 foes when he could get at them. Williston's perfect skull from 

 Dakota enabled him to correct many errors in vogue. The new 

 genus Brachysaurus, formed by Williston, contains one species de- 

 fined by him — Overtoni, from Dakota. It had a stout, very broad 

 head, stout jaws and teeth, and stout, broad paddles. In appearance 

 it suggests a terrible fighter, unadapted to rapid pursuit or flight. 



A number of remarkable skeletons of mosasaurs have been dis- 

 covered of late, some of whicli are expected to develop new species 

 and, perhaps, new genera. Few of the " finds " of explorers create 

 such sensational interest in scientific circles as the unearthing of the 

 gigantic saurians. Three new skeletons were lately taken by an 

 exploring party of the American Museum of ITatural History. Prof. 

 W. T. Lee, of the University of Denver, was so fortunate not long 

 since as to secure the first skeletons of mosasaurs ever taken in 

 Colorado, and adds so much to the geographical distribution of the 

 animals. One skeleton was taken at Flagler and another at Canyon 

 City. The Flagler specimen was exposed for sixteen feet, the verte- 

 bral column containing ninety vertebrae. There were also taken 

 portions of the head and paddles. Flagler is situated in the St. 

 Pierre Cretaceous in all probability. The specimen, not yet named, 

 has a massive jaw and teeth, the latter very compressed. The verte- 

 bral column is one of the most complete yet unearthed. The tail is 

 particularly fine, and gives a good impression of depth and com- 

 pression. 



Williston thinks that the food of the sea-serpentlike saurians 

 must have consisted of fishes of moderate size, with occasional victims 

 of their own kind. He says : " While the flexibility and loose union 



