Geology and Natural History. 115 



a return of freshwater conditions. The westward thinning of the 

 strata in Ohio suggests derivation of the materials from land 

 areas to the east. . . . The sandstones by their mineral composi- 

 tion have evidently been derived at least in part from a source in 



crystalline rocks either igneous or metamorphic It would 



seem from the mineral composition of the sandstones that meta- 

 morphic rocks were not plentiful in the region from which the 

 sediments were derived. Garnet, a common metamorphic min- 

 eral, is entirely lacking in all Carboniferous sandstones of Ohio 

 that have been examined microscopically " (249-251). 



"In regard to the correlation of the fossiliferous beds of the 

 Conemaugh with the Pennsylvanian deposits of Kansas the con- 

 clusion reached is that the Brush Creek and Cambridge lime- 

 stones probably correspond to the middle or upper part of the 

 Pottawatomie formation, the Portersville to the upper part of 

 that formation or the lower part of the Douglas, and the Ames 

 to the upper part of the Douglas or lower beds of the Shawnee " 

 (295). , c. s. 



2. Garadoeian Cystidea from Girvan ; by F. A. Bather. 

 Trans. Roy. Soc. Edinburgh, xltx, Pt. II. Pp. 359-529, 6 pis., 

 80 text figs., 1913. — This is an elaborate study of nine species 

 (eight new) of uppermost Ordovician cystids of the genera Den- 

 drocystis (1), Cothumocystis (2), Cheirocrinus (2), and Pleuro- 

 cystis (4), from the Girvan region of Scotland. The work is, 

 however, much more than a study of the forms and genera men- 

 tioned, for all of the related material of Europe and America is 

 included and finally adjusted into the phyletic classification. 



The final paragraph deserves to be quoted. It reads : 

 " So does the remote story of these Girvan fossils reveal anew 

 the perpetual warfare of life, its ever unaccomplished task to 

 bring this ancestral burden of the body into perfect harmony 

 with an elusive nature ; for, just as that highest hope fails to be 

 fulfilled, the wheel of the world is turned, and the new contest 

 demands competitors of a less wearied stock or a more flexible 

 training. The Palaeontologist may be one who deals with crea- 

 tures that are what we call 'dead and buried,' but he above all 

 men should be filled with a sense of the living drama that under- 

 lies his science : the unending struggle of the past as crystallized 

 in organic form with the ever new surroundings of a shifting uni- 

 verse ; the clash of inherited structure, habit, thought, against 

 the iron necessities of the present. The figured stone, rudely 

 cast aside by the quarryman or blindly treasured by the curio- 

 hunter, is for him an emblem of shattered conventions and creeds 

 outworn ; it is his material proof of the eternal Nemesis." 



c. s. 



3. A Contribution to the Paleontoloyy of Trinidad • by Car- 

 i>otta Joaquina. Maury, with drawings by Gilbert Dennison 

 Harris. Jour. Acad. Nat. Sci. Phila., 2d ser., xv, pp. 25-112, 

 pis. v-xm, 1912. — The work of Guppy has long since attracted 

 the student of Tertiary faunas to Trinidad. As asphalt occurs in 



Am. Jour. Sci. — Fourth Series, Vol. XXXVII, No. 217. — January, 1914. 

 9 



