2d The West American Scientist. 



simplex from Utah, and three others from Colorado. There is 

 also an account of the occurrence of the Chinch Bug in consider- 

 able numbers in California, where, however, it is not yet known 

 to do damage. No. 2 contains, among other things, an account 

 of the Morelos Orange Fruit-worm, which proves to be the larval 

 of a fly-trypeta ludens. The only notes in this number dealing 

 specially with the West are on depredations supposed to be those 

 of the Western Cricket in Colorado, and a notice of the larval 

 habits of Dicerca in the same State. 



T. D. A. C. 



W. G. Smith. On the nesting of Audubon's Warbler (D. au- 

 duboni), in Larimer Co., Colorado, in " Orn. & Ool.," 1888, p. 

 114. 



T. D. A. Cockerell. On the distribution of Aquatic Forms. 

 ''Science Gossip," 1888, p. 182. In this paper the freshwater plants 

 and marine shells and algce of California are compared with those 

 of Europe, and conclusions drawn. There are also various other 

 remarks on Western species. 



ON THE MESOZOIC MAMMALIA. 



For a number of years past Professor Henry F. Osborn of 

 Princeton College, has been assiduously devoting himself to the 

 study of the taxonomy and morphology of the Mesozoic Mamma- 

 lia, and in these investigations, this eminent paleontologist has 

 been materially, assisted by having been allowed the free use of 

 the invaluable collections formerly utilized by Professor Sir Richard 

 Owen, and now preserved- in the British Museum, as well as the 

 collections of Dr. Lemoine, of Rheims, and the American collec- 

 tions of Cope and Williams College. Enjoying such opportuni- 

 ties as these, and worked over by such a hand, we naturally lQok 

 for more than ordinary results, and science is by no means dis- 

 appointed in the matter. Professor Osborn' s labors now come 

 before us in the form of a magnificent royal quarto monograph 

 of some seventy-five pages, and published by the Academy of 

 Natural Sciences of Philadelphia, (Vol. IX, No. 2, July, 1888.) 

 It is illustrated by thirty wonderfully clear woodcuts in the text, 

 and two very fine lithographic plates, the handiwork of the fam- 

 ous house of Sinclair & Son, which is sufficient guaranty of their 

 excellence. These drawings are all devoted to either the jaws or 

 the dentition of the group under consideration, and amply illus- 

 trate the remarks of the author. 



Formerly it was generally supposed by paleontologists, that 

 the mammalian fauna of the Mesozoic period were of very lim- 

 ited number, as so late as 1871, Professor Owen, in his well- 

 known monograph, described but twenty genera, while in the 



