1891.] Progress of American Invertebrate Paleontology 327 
REVIEW OF THE PROGRESS OF AMERICAN INVER- 
TEBRATE PALEONTOLOGY FOR THE YEAR 1890. ` 
BY CHARLES R. KEYES. 
KENGE the last consideration of the subject in this journal im- 
portant contributions to American invertebrate paleontology 
have been made. The number of titles is considerably in excess 
of that of last year. Several extensive state reports have 
appeared ; but the large majority of the papers issued have been 
incorporated in serials. With the exception of a few brief pres- 
entations on small zoological groups no monographical works 
have been distributed during the year just closed. The several 
great works alluded to last year as in an advanced state of prepa- 
‘ration have been necessarily delayed by the discoveries of much 
new material; but the evidence at hand clearly indicates that the 
delay will not be unaccompanied by more suggestive results than 
could otherwise have been reached. 
Excepting those proposed in a single brochure which has not 
as yet been generally distributed, the number of new species con- 
sidered is very much below that of any similar period during the 
past decade, thus greatly emphasizing the statements made in the 
last “review.” On a former occasion the fact was mentioned 
that the interdependence of the stratigraphical geologist, the 
biologist, and the paleontologist is constantly becoming more and - 
More intimate. This suggestion has never been more fully cor- 
roborated than by the recent appearance of several most valuable 
morphological memoirs, based largely upon critical studies of 
extinct forms of life. Nor is the reality of the remark less appar- 
ent in certain late articles dealing with problems of stratigraphy. 
In the annual report (pp. 116-120) of the Geological and Nat- 
ural History Survey of Canada, Henry M. Ami has a Systematic 
List of Fossils with Localities referred to in Report K. 
Charles E. Beecher, has in the American Journal of Science (3), 
Vol. XL.: North American Species of Strophalosia, pp. 240-246; 
On Leptzenisca, a New Genus: of Brachiopod from the Lower 
