220 Scientific Intelligence. 



In the Perrno-Carboniferous beds of North America the author 

 notes the occurrence of 14 genera and 22 species of fishes, 22 genera 

 and 45 species of amphibia, and 49 genera and 75 species of rep- 

 tiles. Of these, 17 forms occur in Illinois, 3 in Pennsylvania, 

 and 1 on Prince Edward Island, the rest being found in Texas 

 (107), Oklahoma (24), New Mexico (17), and Kansas (2). No 

 less than 18 genera are illustrated as they are supposed to have 

 looked in the flesh. 



"The amphibians show the universal carnivorous dentition ; 

 the teeth in all are simple, conical, grasping organs with slight 

 j)Ower of mastication. . . . Among the reptiles a greater variety 

 of food habits is indicated by the character of the teeth, but so 

 far no form has been discovered which can be reckoned as purely, 

 or even largely, herbivorous. Some are clearly pure carnivores ; 

 others may have included some portion of vegetation in a diet 

 composed largely of hard-shelled molluscs" (101-102). 



" One feature of the Permo-Carboniferous vertebrate fauna 

 which has, from its striking character, attracted much attention, 

 is the presence of several forms which have developed, to a 

 remarkable degree, spines, horns, excrescences, etc. The number 

 and importance of these over-specialized forms have been exag- 

 gerated, because of their peculiarity, but a careful survey of the 

 fauna, especially when an attempt at restoration is made, reduces 

 this feature to a position of much smaller importance than was 

 originally supposed " (111). 



" Considering only the region in Texas and Oklahoma, which 

 is typical of all the Red Beds, we may restore in imagination a 

 great flat land stretching away from the Wichita Mountains and 

 the Arbuckle Hills to the east and south, where it joined the 

 ocean waters. The western border of the flat we do not know. 

 The normally semiarid condition of the land was interrupted by 

 incursions of the sea and fluctuations of the climate to more 

 humid conditions. . . . Upon this flat, largely around the pools 

 and streams, lived the wonderfully complex amphibian and 

 reptilian life. The waters swarmed with fish and amphibians, 

 and were constantly invaded bv predaceous reptiles in search of 

 food" (147). 



" Another thing that must be constantly kept in mind is that 

 the remains are not found in their natural habitat. In only a few 

 cases can it be s'hown that the animals have been buried near 

 where they lived or died. Rivers or currents in larger bodies of 

 water have borne the carcasses away after death, and in any 

 attempt to picture the natural habitat this must be reckoned 

 with " (148-149). 



" The fauna of North America was, so far as the author can 

 see, an isolated one, prevented from any mixture with other 

 groups of animals by an isolation of the continent from Europe" 

 (150). This isolation seems to the reviewer to be due rather to 

 climate (aridity) than to the separation of the continents. 



Professor Case's studies have led him to conclude that the 

 evolution of the reptiles was different in North America and 



