Geology. 547 



ton. Contrib. from Walker Museum, 2, No. 4, pp. 75-112, pis. 3, 

 4, text figs. 1-19, 1918. — The first paper, as the title indicates, 

 treats of the evolution of the vertebrae, and upholds the concep- 

 tion first worked out by Cope. The Stegocephalia in the Temnos- 

 pondyli have divided vertebrae, inherited from the fishes. Out of 

 this stock with embolomerous vertebrae arose the reptiles in the 

 late Paleozoic. The succeeding changes are then traced through 

 the various orders of reptiles. 



In the second paper, the author discusses the skulls and other 

 parts of the skeleton of Eryops, Chenoprosopns, Naosaurus, 

 Sphenacodon, and the new genus Platyops. Both papers are 

 fully illustrated by excellent drawings made by the author. 



c. s. 



4. Onaping Map-area; by W. H. Collins. Geol. Survey 

 Canada, Mem. 95, 157 pp., 11 pis., 8 text figs., 2 maps, 1917. — In 

 this memoir are clearly described the pre-Cambrian rocks of the 

 Onaping area lying to the north of Georgian Bay and Sudbury, 

 and their economic content. The geologic succession is as fol- 

 lows: Pleistocene thin glacial deposits; great unconformity; 

 Huronian division, separated into the upper basic intrusives 

 (= ?Keweenawan) and the lower Cobalt series; great uncon- 

 formity; pre-Huronian highly metamorphosed division, which 

 includes the younger granite-gneiss bathyliths, and below, the 

 great schist complex. Collins prefers for the present to use the 

 term pre-Huronian rather than Keewatin, Laurentian, or Algo- 

 man. This because "no reliable classification of the pre-Huron- 

 ian can be made until a correlation datum plane has been 

 established within the pre-Huronian" area. c. s. 



5. Timiskaming County, Quebec; by M. E. Wilson. Geol. 

 Survey Canada, Mem. 103, 197 pp., 16 pis., 6 text figs., 1 map, 

 1918. — This is an interesting report describing the pre-Paleozoic 

 formations or the basal complex, the physiography, and the 

 economic geology of the area, along with a presentation of its 

 special problems. The interesting Huronian tillites are also 

 described, and the small area of Paleozoic strata is believed to 

 be a down-faulted mass into the basal complex, or more specifi- 

 cally, into the Abitibi group. The Keweenawan, or Nipissing 

 diabase, is referred with doubt to the pre-Cambrian, and 

 the Huronian (Cobalt series) and the Basal Complex definitely. 

 The latter includes the pre-Huronian bathyliths, the Abitibi 

 group and the Grenville series. c. s. 



6. The Pliocene History of northern and central Mississippi; 

 by Eugene W. Shaw. U. S. Geol. Survey, Prof. Paper 108-H, 

 pp. 125-163, pis. 45-60, text figs. 21-25, 1918.— This good work is 

 of especial interest in pointing out that the long misinterpreted 

 Lafayette formation is not a depositional unit, and that most of it 

 is weathered material belonging to various underlying formations. 

 In the opinion of Mr. Shaw, "the material called 'Lafayette 



