354 



SCIENCE 



[N. S. Vol. XLIII. No. 1106 



concepts are quite novel, will be able in gen- 

 eral to follow the author's reasoning. 



Howard C. Wakben 

 Princeton Univeesitt, 

 February 8, 1916 



The Permo-Garboniferous Red Beds of North 

 America and Their Verteirate Fauna. By 

 E. C. Case. Carnegie Institution of Wash- 

 ington. 



In this monograph Dr. Case has summarized 

 our knowledge to date of the vertebrates from 

 these Permo-Carboniferous beds, which, for a 

 period of over forty years, have been yielding 

 remains of essential interest to paleontology; 

 because the beds, laid down at a time when 

 the amphibians were dominant and the rep- 

 tiles were in the transitional stages, have pre- 

 served the most complete skeletons of these 

 early vertebrates, and it is essential to know 

 these Cotylosaurs, Pelycosaurs, etc., in order 

 to attain a correct idea of the further develop- 

 ment of the reptiles and the ancestry of the 

 mammals. 



His careful description of the beds and 

 localities invites and clears the way for those 

 who shall follow and collect in these beds, the 

 tedious search for favorable localities and 

 horizons, which hampered the pioneers in this 

 field, being removed by the submission of all 

 this data to the public; and it is a hard field, 

 the fossils being scarce and fragmentary. 

 Then his conclusions from the character of 

 the beds as to the climates and environment 

 are a great aid in the efforts to interpret evo- 

 lution. 



Case gives the range of this fauna as from 

 the Pittsburgh Eed Shales in the middle of 

 the Upper Pennsylvanic (Missourian) to the 

 top of the Clear Fork, which is about the 

 middle of the Permic, as described by Schuch- 

 ert. At this point in time the dominance of 

 this fauna ends in America, though in Europe, 

 it, or an equivalent fauna, runs up into the 

 Triassic. 



It is shown that all the amphibians of the 

 fauna are carnivorous, the reptiles partly car- 

 nivorous, partly molluscivorous, and partly 

 insectivorous. None were adapted to marine 

 life; none were far advanced even toward 



fresh water life; but the fauna is typically 

 one of the estuaries, swamps, alluvial plains 

 and woodlands. 



The eighth chapter presents summary de- 

 scriptions of the best-known genera, illus- 

 trated by 23 restorations, which impress the 

 reader with the heavy, slow-moving character 

 of most of these animals, though the drawings 

 leave something to be desired in life-like 

 appearance. 



An appendix gives a description of the Brier 

 Creek Bone Bed and its fauna, the locality 

 which has yielded the richest finds of Permo- 

 Carboniferous vertebrates. Some twenty 

 plates show detail photographs of the beds and 

 fossiliferous strata, which will aid any one 

 studying the conditions of deposition, or going 

 into this field, so that with the minimum of 

 experience they can get the best results. 



As a whole the volume is one which will ably 

 serve any student of the Permo-Carboniferous, 

 as it brings him up to the present, and will 

 long serve as the starting point for further 

 studies of these beds. P. B. LooMis 



Amherst College 



SPECIAL ARTICLES 



AN ELECTRIC COUNTER FOR DETERMINING 



THE RATE OF A FREE-SWINGING 



PENDULUM 



A HEAVY pendulum, vibrating through small 

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