August 30, 1901. ] 



SCIENCE. 



331 



centals after the later Cretaceous, aud tlie con- 

 clusion is reached that since the Placentals have 

 radiated from a Creodont prototype beginning 

 in the later Cretaceous period, it is quite pos- 

 sible that the Marsupials have during the same 

 time radiated from a DideJphys prototype ; there 

 is a striking general resemblance between the 

 early Creodonts and the opossum which tends to 

 supi^ort this theory. It is practically the work- 

 ing out of a hint by Huxley in 1880, and of a 

 very suggestive paper by Dollo upon the arbo- 

 real ancestry of the Marsupials. The idea of 

 Dldelpliys origin, however, is original with Mr. 

 Bensley, and the detailed comparison of the 

 evolution of the teeth of Marsupials with that 

 of Placentals promises to give most important 

 and interesting results. Mr. Bensley is enjoy- 

 ing the extensive collections of the British 

 Museum. 



GEOLOGY OF THE JOHN DAY BASIN.* 



As a result of the explorations by the Univer- 

 sity of California, John C. Merriam contributes a 

 valuable paper upon the geology of this impor- 

 tant region in Oregon, as preliminary^ to the re- 

 vision of the vertebrate fauna. Although this 

 region was first reported in 1861 and explored 

 by Condon, Marsh, Cope, Scott, Sternberg 

 and Wortman, this is the first exact description 

 of its geology, and is therefore most welcome 

 and important. The author divides the beds 

 into the Lower (250-300 feet), which is re- 

 ported to contain Oreodon ; Middle (500-1,000 

 feet), chiefly distinguished by Diceratherium ; 

 and Upper, which contained Paracoiylops. The 

 exact correlation of these beds with those of 

 the Oligocene White River awaits the precise 

 comparison and study of the faunae. The mode 

 of deposition has generally been considered en- 

 tirely lacustrine, as the series are everywhere 

 uniformly stratified and bedded, on the other 

 hand, the author presents strong reasons for an 

 seolian origin for the finer portions of these beds. 

 In fact the problem is precisely similar to that 

 which is now being discussed for the finer beds 

 of the White River formation. 



* ' A Contribution to the Geology of the John Day 

 Basin,' Bulletin, Dept. of Geology, Univ. of Cali- 

 fornia, Vol. II., No. 9, pp. 269-314, April, 1901. 



DISCOVEEIES OF PLESIOSAURUS AND OF POR- 

 THEUS. 



During the past season Mr. Charles H. 

 Sternberg, well known for his years of ex- 

 plorations in the Kansas Chalk, made two dis- 

 coveries of exceptional importance. The first is 

 of a new typeof Plesiosaur, the skeleton of which 

 is preserved in an exceptional manner ; this has 

 been purchased by the University of Kansas aud 

 will be described by Professor Williston as part 

 of his general studies upon Plesiosaurs. The 

 second is a remarkable skeleton of Poriheus 

 molossus, of the suborder Acauthopteri, 

 family Ichthyodectidse — the characteristic pre- 

 daceous fish of the Niobrara. The specimen 

 is sixteen feet in length and is in an excep- 

 tional state of preservation. It has been pur- 

 chased by the American Museum of Natural 

 Histoi'y, and will be mounted facing the great 

 specimen of Tylosaurus from the Kansas Chalk 

 which has already been described in this 

 Journal. H. F. O. 



BOTANICAL NOTES. 

 SHORT NOTES ON RECENT BOOKS. 



Among botanical books which are likely to 

 attract attention is Dr. Wettstein's ' Handbuch 

 der Systematischen Botanik' of which Part 1 

 (including pages 1 to 202) has been brought out 

 by the Leipzig publisher Franz Deuticke. Re- 

 sembling Warming's ' Haandbog i den Syste- 

 matiske Botanik ' and Schumann's ' Lehr- 

 buch der Systematischen Botanik,' it promises 

 to be much fuller and more helpful than either, 

 and like them is to be a general survey of the 

 structure and classification of the Vegetable 

 Kingdom. The attempt is made to treat the 

 subject from the phylogenetic standpoint, and 

 whatever of success is attained in the work is 

 largely due to this fact. In the part now is- 

 sued forty-four pages are given to a general 

 discussion of the principles involved, followed 

 by the special discussion of representatives of 

 the seven phyla recognized by the author, viz. : 

 Myxophyta (including the single class Myxo- 

 mycetes), Schizophyta (including the classes 

 Schizophyceae and Schizomycetes), Zygophyta 

 (including the classes Peridineae, BaciUarieae 

 and Conjugatae), Euthallophyta (including the 

 classes Chlorophyceae and Fungi, the latter in- 



