72 THE ZOOLOGIST. 



NOTICES OF NEW BOOKS. 



Water Reptiles of the Past and Present. By Samuel Wendell 

 Williston. University of Chicago Press. 



Professor Williston's book, well illustrated by figures, 

 many of which are by himself, is a welcome addition to the 

 literature of extinct animals, more especially as particular 

 endeavour has been made — and made successfully — to make 

 the subject understandable to the non-scientific reader. The 

 extinct sea-reptiles have always enjoyed a particularly wide- 

 spread reputation, their remains being so numerous and well- 

 preserved, so that the Ichthyosaurs and Plesiosaurs in particular 

 are quite well known, as extinct forms go. There is much 

 information about them here which will be new to many who 

 have a general knowledge of them ; full prominence is given to 

 the external form of the Ichthyosaurs, now well known by 

 fossilized outlines to have possessed a caudal fin, which Owen 

 inferred they possessed, and several types of Plesiosaurs are 

 discussed and figured, not only the familiar long-necked forms, 

 but others with necks of varying length, including some whose 

 necks were shorter than the head, which was broad. These, 

 therefore, made some approach to the Crocodiles in form, and 

 some of them with skulls five feet long armed with teeth, some 

 of which were four inches in length, must have been more 

 formidable than any other sea-reptiles. The author must be for- 

 getting these when he says that the snake-like reptiles of the 

 Mosasaurian or Pythonomorph group would probably be the 

 only sea-reptiles dangerous to man, were ail existing to-day. 

 The Mosasaurs, however, were undoubtedly a very truculent lot, 

 and the frequent injuries displayed by their remains show that 

 they probably fought each other. 



Curiously enough, young of this group have never come to 

 light, and it is suggested that they may have been oviparous. 

 In this case- they no doubt came ashore to breed, though it is 

 pointed out that their paddles, although less specialized than 



