RevieiDS — A. Smith Woodward's Vertebrate Palceontohgy. 373 



As this volume is designed for the use of students, it may not be 

 improper to suggest that in every case where veto terms are intro- 

 duced a gloss should be given explanatory of such terms. 



Again, it is hardly consistent to place Tritylodon (p. 154, fig. 97) 

 with the Theriodonts, as a matter of course, if it has (as the 

 author admits) been commonly ascribed to the Mammalia by Owen 

 and others who have written upon the subject ; whilst Polijmastodon 

 (p. 253, fig. 149 B), with precisely similar multituberculate molars 

 and similar number of incisors, remains unchallenged and is admitted 

 as one of the Prototheria. 



And why should " other double-roofed multituberculate teeth 

 from the Rhfetic of Europe, commonly claimed as mammalian " 

 (p. 248), be suspected of being Anomodonts in disguise? 



The illustrations of amphibian and reptilian skulls, and of mam- 

 malian teeth, have in some instances been borrowed from authors 

 whose views as to their interpretation are not quite the same ; as 

 a consequence we have the nomenclature given in one illustration at 

 variance with that given in another. In one case, for instance, on 

 p. 143, fig. 91, the squamosal and supratemporal change places in 

 figures B and E. 



In fig. 183, p. 323, the cheek - teeth of Syracotherium (after 

 Wortman) ; fig. 185, of Palceotherimn (after Gaudry) ; fig. 187, 

 MesoJiipjms (after Osborn) ; and fig. 189 (after Earle), the references 

 do not always agree ; the cones being differently lettered. In the 

 fourth premolar Gaudry's paracone E is equal to the protocone in 

 the other figures. 



One is inclined to question the advisability of the adoption of the 

 terms Asterospondyli and Tectospondyli, in place of the time-honoured 

 and well-known Selachoidea and Batoidea, especially as these 

 terms are based upon the minute structure of the vertebrge (radiations 

 being more pronounced in one and concentric layers in the other), 

 structures which are not easily to be made out, and whose absolute 

 constancy one might be inclined to doubt. 



There is a good table of geological periods given, facing p. 411 ; 

 but in the blank part folded for drawing out the table, there 

 is ample space afforded to have given four columns for the leading 

 groups of Fishes, Eeptiles, Birds, and Mammals, briefly summarized, 

 which might have proved exceedingly useful to the palaeontologist. 



On the whole, we like the book very much, and consider it 

 distinctly in advance of any similar effort in Vertebrate Paleeontology. 



The geographico-geological chapter at the end is useful, and 

 contains much good matter. Why, we may ask, should the 

 Protospondyli of the Jurassic be spoken of as the dominant race of 

 vertebrate life ? One would suppose the Sauropterygia and the 

 Ichthyopterygia were the dominant aquatic races of vertebrate life, 

 and the Dinosauria the terrestrial reigning type. 



But let the work stand upon its own feet ; we have commended 

 it, and we will stand by our word. Those who desire a good book 

 on Vertebrate Paljeontology will certainly do well to procure a copy 

 for their reference library. 



