Geology. 439 



are described 10 plants from the Midway formation and over 

 300 species in 134 genera from the Wilcox formation. The 

 work, however, is far more than a description of species and 

 genera, as 145 pages are devoted to the sections yielding the fos- 

 sils, the distribution of the floras, their character and ecology, 

 and the correlation of the Wilcox formation. The plants from 

 the Wilcox, which Berry correlates in part with the Fort Union 

 and the Wasatch, are almost wholly angiosperms (94 per cent) 

 and represent a coastal or strand flora under a climate about like 

 that of the Florida Keys. c. s. 



4. On some Permian Brachiopoda of Armenia; by A. 

 Stoyanow. Mem. Comite Geologique, n. s., Liv. Ill, 1915,95 

 pp., 6 pis. — The author here describes fully, in Russian and in 

 English, his genus Tschernyschewia proposed in 1910. At first 

 sight the form looks like a sinused Productus, but as it is attached 

 by the ventral beak, has a long and narrow cardinal area that is 

 bisected by a delthyrium and covered by a very delicate del- 

 tidium, with a very high median ventral septum, it is seen to be a 

 genus quite different from all known productids. He also dis- 

 cusses Richthofenia, Scacchinella,, Tegulifera, and Productus. 



c. s. 



5. Cambrian Geology and Paleontology, Hi, No. 5, Cambrian 

 Trilobites ; by Charles D. Walcott. Smiths. Misc. Coll., vol. 

 04, pp. 303-456, pis. 45-67, 1916.— The author here describes 17 

 genera or subgenera (9 new) and 85 species (54 new) of Cambrian 

 trilobites. Probably the most interesting genus is Pagetia, a 

 form not unlike Agnostus, with free cheeks and eyes on the 

 dorsal surface of the animals. c. s. 



6. Checklist of the Recent Bivalve MollusJcs (Pelecypoda) of 

 the Northwest Coast of America from the Polar Sea to San 

 Diego, California; by William Healey Dall. Published by 

 The Southwest Museum, Los Angeles, 44 pp., 1916. — In this 

 interesting checklist .Dal I lists 474 species and varieties of bivalves 

 living off the northwest coast of North America down to San 

 Diego. Of these, 45 are deep-water forms restricted to waters 

 below 60 fathoms in depth. There are therefore 429 shallow- 

 water forms and of this number 205 are restricted to one of the 

 three provinces (77 to the Arctic, 17 to the Temperate, and 111 

 to the Tropical), so that about one-half of the shells (219) have a 

 geographic range over two of the provinces. This is the second 

 publication by the new Southwest Museum of Natural History in 

 Los Angeles. c. s. 



7. Interrelations of the Fossil Fuels. Part I ; by John' J. 

 Stevenson. Proc. Amer. Philos. Soc, Iv, pp. 21-203, 1916. — 

 In this valuable and comprehensive work the author brings 

 together all that is known regarding the Pleistocene and Recent 

 peats and the coals of the Tertiary. His wide knowledge of the 

 Paleozoic coals and his great industry enable him to summarize 

 the voluminous literature bearing upon the problems in hand in 

 a clear manner. The area of the peats " is apparently greater 



