150 Scientific Intelligence. 



( = 11 ft. 1 in.) to P. ingens type (Cat. No. 1175) with 6-803" 1 

 ( — 22 ft, 3 in.). Still another individual (Cat, No. 2514), if the 

 proportions of the known bones were carried out, would have the 

 tremendous expanse of 8"163 m or 2G feet 9 inches! 



The geologic and geographic localities of the seven described 

 specimens are given — all from the Niobrara chalk of Wallace 

 and Trego counties or from the Smoky river in western Kansas. 



It is' to be regretted that a specific summary was deemed 

 inadvisable, for the author was certainly better fitted than any 

 one else to attempt such revision. Nothing is said as to relation- 

 ships with other Pterosaurs or of the life conditions other than 

 the following brief suggestion on page 13: 



"The occurrence of Pteranodon remains in the chalk deposited 

 in a shallow sea and at a distance of not less than one hundred 

 miles from the probable shore line, also the shape and proportion- 

 ate size of the jaws, have given rise to the supposition that this 

 pterodactyl lived principally upon small fish taken at the surface 

 in a manner somewhat similar to that adopted by the Skimmer, 

 Rhynchops." 



The only suggestion in the way of a cause of extinction is the 

 danger of parturition, owing to the development of crest and 

 wing bones "the immoderate proportions of which, however, were 

 probably due entirely to postnatal growth." 



Mr. Eaton has done an excellent piece of descriptive work and 

 the plates, prepared from photographs and pen drawings, are 

 admirable. B. s. l. 



2. The Age of Mammals ; by Heney Fairfield Osborn. 

 Pp. i-xvii, 1-635, with 220 text figures. New York, 1910 (The 

 Macmillan Company). Price $4.50 net. — This admirable book in 

 its present form is the outcome of the series of Harris lectures 

 delivered in 1908 before the students of Northwestern University. 

 Many of the facts set forth are of course known to men of sci- 

 ence, especially to such as have had the privilege of being 

 Osborn's pupils, but the assembling of the great array of truths 

 to find which one would have to go far afield or delve into various 

 sources, often in foreign tongues, is a work of the utmost value 

 to the student and teacher of mammalian life and likewise to the 

 serious reader. The problems discussed are not those of the 

 evolution and descent of the various phyla, but rather the sources 

 of origin of the various mammalian groups, their wanderings 

 over the face of the globe and the final extinctions of the races 

 which have passed away, together with the competition of the 

 elements of the successive faunas in time and space. 



Paleogeography, the climatic changes and the consequent evo- 

 lution of plant life, which form the fundamental factors influenc- 

 ing animal change, are fully discussed, illustrated by excellent 

 geologic and geographic charts. Of the mammals themselves, 

 the great array of fossil skeletons in the American Museum 

 together with the well-known restorations in the flesh by Charles 

 R. Knight form most ample and admirable illustrations. Espe- 







