266 KANSAS UNIVERSITY SCIENCE BULLETIN. 



not bottom feeders, like the sirenians. At the same time they 

 must have traveled or migrated long distances in the water. 

 The siliceous pebbles, so often found with their remains in the 

 Kansas chalk, could only have been obtained hundreds of miles 

 away, for they are absolutely unknown away from the remains 

 of these animals. 



The ichthyosaurs are known to have fed upon cephalopods 

 and other invertebrates, if the coprolites ascribed to them are 

 really ichthyosaurian. I believe that the plesiosaurs, or many 

 of them, fed largely upon such food, living along the shores in 

 comparatively shallow water, and were not accustomed to go to 

 considerable depths ; that is, they lived for the most part near 

 the surface of the water. Evidence presented by Seeley years 

 ago seems to indicate that they were viviparous in habit like the 

 ichthyosaurs, though such evidence has not been forthcoming in 

 America. It is a singular fact that embryonic propodial bones of 

 plesiosaurs are not at all rare in the Kansas chalk. There are 

 five such bones in the Kansas museum collection, and I have 

 seen perhaps a score of others. These bones are always found 

 isolated, and were for a long time very problematical. In some, 

 the peculiar epiphysial structure is beautifully shown. In all, 

 there are several foramina perforating the middle, with a groove 

 leading therefrom corresponding to the ent- or ectepicondylar 

 groove of the testudinates and mosasaurs. The conical 'epiphy- 

 ses' terminate at these canals. 



"Entsprachen die soeben gegebenen Ausfiihrmigen den Thatsachen, 

 so kann man sich die Plesiosaurier audi nicht langer als auf der 

 Oberfache des Meeres, etwa wie Sclmimmvdgel lebende Geschopfe 

 vorstallan, sondern sie haben, wie die Ichthysaurier, unter der Ober- 

 flache im Meera gelebt." 2 



This conclusion of Dames I have no doubt is correct. His 

 restoration (1. c, p. 79), I believe, is somewhat faulty in the 

 two angular caudal expansions and in the pedunculation of the 

 limbs. I believe the latter were broader proximally, as was 

 certainly the case in both the ichthyosaurs and mosasaurs. 



It is evident from the great variations in form among the 

 plesiosaurs that they varied not a little in habits. Though ex- 

 ceeding in size the largest mosasaurs, I do not think that they 

 were ever a match for them in prowess or voracity. Like the 

 gavials, they were comparatively harmless creatures. 



2. Dames, Abh. Konigl, Preuss. Akad. S. Wissensch., 1895, p. 79. 



