Geology and Natural History. 467 



inasmuch as meteorites and the dust of meteorites are constantly- 

 falling upon the earth, to the extent of probably many million 

 tons a year. Further information upon the question of the pres- 

 ence of gold in meteorites is promised in a subsequent paper. 



9. Triassic Ichthyopterygia from California and Nevada ; by 

 John C. Mereiam. Bulletin of the Dept. of GeoL, Univ. of 

 Cal., vol. iii, No. 4, pp. 63-108, pis. 5-18. — A valuable contribu- 

 tion to Paleontology, based chiefly upon saurian material from 

 the upper Triassic of Shasta County, California, collected in 1891 

 by field parties from Stanford and California universities. 



The great value of the monograph under review lies in the 

 carefully executed plates and in the accurate measurement and 

 description of the bones of a hitherto little known group of 

 extinct reptiles. Collectively, the several specimens described 

 afford an excellent generic definition of Shastasaurus, the anterior 

 part of the skull and the distal ends of the paddles being practi- 

 cally the only portions of the skeleton which now remain unknown. 

 Prof. Merriam has met with the great, though by no means rare, 

 good fortune to find in his collected material nearly as many 

 species of Shastasaurus as individuals, seven examples offering 

 more or less complete descriptions of five new forms, S. perrini, 

 osmonti, alexandrce, careyi, and aUispinus, although none of the 

 new acquisitions have been identified with the type species S. 

 pacifcuSf which was described by him in 1895 (this Journal, 

 vol. iv, p. 56). The type species is shown to differ from S. per- 

 rini in regard to certain posterior dorsal vertebrae and the pubis. 

 None of the other new species, however, are represented by these 

 parts, and therefore cannot well be differentiated from the type. 

 The author wisely states : " At the present time we cannot deter- 

 mine definitely the relations of pacificus to the better known 

 species, and it is not impossible that when the other parts of the 

 skeleton of those forms are better known it will be found that 

 some one of them should be included in pacificus.'''' In view of 

 this lack of comparison and the urgent need of simplicity, the 

 doubt naturally arises whether the purpose of classification would 

 not have been better served by uniting, provisionally at least, one 

 of the new forms with the type species. 



Accompanying the discussion of Shastasaurus is a careful 

 revision of Leidy's genus Cymbaspondylus from the middle Tri- 

 assic of Nevada, which is shown to be closely related to Shasta- 

 saurus. The family Shastasauridse is proposed to embrace these 

 two genera, distinguished as they are from the Mixosauridae, 

 Ichthyosauridse, and Baptanodontidse, by the peculiar articulation 

 of their dorsal ribs, the form of the pelvic girdle, and their long- 

 spined chevron bones. In a postscript, Prof. Merriam states that 

 a good collection of saurian material has just been obtained from 

 the middle Triassic of Nevada. When these specimens have been 

 properly worked out, another contribution is promised by the 

 author. This will be awaited with great interest, and it is confi- 

 dently hoped that further investigation will yield as satisfactory 

 results as the monograph before us. g. f. e. 



