Geology. 241 



Upper Jurassic) describes 35 species, 30 being new. One form 

 is from the Ellis formation of Montana, and may indicate an 

 horizon somewhat older than the Sundance; another is from 

 British Columbia; three are from the basal beds of the Naknek 

 formation of Alaska ; and thirty from the Sundance of Wyoming 

 and South Dakota. In these places are found only the genera 

 Cardioceras and Quenstedticeras, Amoeboceras being restricted 

 to the Mariposa slates of California, apparently the youngest 

 Jurassic horizon in the United States. c. s. 



17. Paleontological Correlation of the Fredericksburg and 

 Washita Formations in North Texas; by W. S. Adkins and W. 

 M. Minton. Univ. of Texas Bull. No. 1945, 128 pp., 21 pis. 6 

 text figs., 1919 (1920) . — After six years of work on the Comanch- 

 ian strata of northern Texas the authors have learned the strati- 

 graphic range of the various invertebrate fossils. The forma- 

 tions, on the basis of lithology, change very rapidly from place to 

 place, either from south to north or from west to east. Accord- 

 ingly, fossils are the only safe means of correlation, and on this 

 basis the Fredericksburg and Washita series are here divided into 

 41 f aunal ' ' horizons, ' ' each typified by guide fossils. The authors 

 have more than 100 new species, but in this memoir only 11 of 

 them are described. To make clear their understanding of the 

 guide species, they here describe and illustrate 74 forms, but 12 

 of them are not specifically named. Of cephalopods there are 20, 

 bivalves 30, gastropods 2, brachiopods 1, echinids 17, corals 3, 

 and foraminifers 1. The authors are to be congratulated on the 

 good beginning they have made toward a final zoning of the 

 Comanchian of Texas. c. s. 



18. Fossils from the Miura Peninsula and its immediate 

 north; by Matajiro Yokoyama. Jour. College of Science, Im- 

 perial Univ. of Tokyo, 39, Art. 6, 193 pp., 19 pis., 1 map, 1920.— 

 In this memoir are described 229 species of Mollusca, and 6 of 

 Brachiopods, from the lower Musashino formation occurring to 

 the south of Yokohama. Of these, 93 are new. The fauna has 

 boreal relations and is of colder waters than at present exist in 

 the same latitude. The horizon is thought to be Pliocene, and 

 the number of forms still living is about 95, or 40 per cent of the 

 fossil fauna. The heliotype illustrations are very fine. 



c. s. 



19. North American Early Tertiary Bryozoa; by Ferdinand 

 Canu and Ray S. Bassler, U. S. Nat. Mus., Bull. 106, text and 

 plates, 877 pp., 162 pis., 279 text figs., 1920.— Previous to the ap- 

 pearance of this great monograph, there had been identified of 

 American Eocene and Oligocene bryozoans but 81 forms, 

 arranged in about 40 genera. We are told, however, that Ter- 

 tiary bryozoans "often occur literally by the millions in a 

 stratum." Canu and Bassler now describe from the Atlantic 

 and Gulf border (Maryland to Mississippi) Eocene and Oligocene 

 (52 stations) about 742 forms in 266 genera, of Cheilostomata 



