R. P. Whitfield—Fossil Crustaceans from Ohio. 33 
Art. VIL.—WNotice of New Forms of Fossil Crustaceans from the 
Upper Devonian Rocks of Ohio, with descriptions of New Gen 
era and Species; by R. P. WHITFIELD.* 
In the 16th Report of the State Cabinet of New York, 
there is described and figured a peculiar bivalve crustacean 
from the Hamilton formation of New York, under the name 
Ceratiocaris punctatus. It is again repeated on Plate 28, fig. 7, 
_of the Illustrations of Devonian Fossils, Section Crustacea, under 
the name Ceratiocarts (Aristozoe) punctatus. Among the fossils of 
the Ohio Geclogical Survey, there are represented three species 
of similar form, but specifically distinct from the above; and I 
have seen examples of at least two species from the Hamilton 
and Chemung groups of New York, which may be distinct 
these. 
s in t 
Leperditia and its allies; while the forms under consideration 
are provided with a bivalve or, at least, a two-sided carapace, 
which incloses the thoracic portions; while the abdomen and 
caudal parts are naked, or not inclosed within this covering; 
and are more properly classed among the Phyllopods. 
That this latter character, the naked abdomen and caudal 
plate, pertains to these organisms, is abundantly proven by the 
Ohio specimens now under consideration. The fossils are 
tion; so we may safely conclude, that, where parts or frag- 
ments of individuals of corresponding size are found in the 
of the species. All the specimens are from the 
* These descriptions will be repeated in vol. iii, Paleont. Ohio, with illustrations 
i cabinet of Dr. J. 8. Newberry. 
Am. Jour, a Series, VoL, XIX, No. 109.—Jan., 1880, 
