FOSSIL ASTACIDA. 155 
No remains of Crustacea near the Astacidee have been found in the Wealden, which 
is of fresh-water origin, while the Cretaceous has yielded the genera Hoploparia and 
Enoploclytia, which closely resemble the recent Homaridee. Hoploparia is found also in 
the London Clay (Eocene). 
Schliiter* has described, under the name Astacus politus, a Decapod from the Lower 
Chalk of Westphalia, in which the telson is divided by a transverse suture, as in the 
majority of the Potamobiine ; but the single specimen obtained is too imperfect to admit 
of being definitely placed, the fore part of the carapace, including the rostrum, as well as 
the terminal portion of all the legs, being lost. 
It is only in the fresh-water Tertiary deposits of the Western United States that fossils 
have been discovered which can be referred reasonably to the family Astacide. Packard 
has described and figured by the name of Cambarus primevus two specimens from the 
Lower Tertiary beds (Eocene ?) of the Bear River Valley in Western Wyoming. Judging 
from Packard’s figures, I should think that these specimens belonged to Astacus rather 
than to Cambarus. The shape of the antennal scale and the chele indicate this. I fail 
to see the close resemblance pointed out by Packard between these specimens and Caim- 
barus afinis. The rostrum, as shown in the figures, resembles that of A. Dauricus as 
nearly as any living form. With reference to the conditions under which these crayfishes 
lived, Dr. Packard says: “The soft, fine, fissile, clayey shales of the Bear River Tertiaries 
contain not only a good many herring-like fish, but also genuine skates. The presence 
of land plants mingled with marine animals shows that the waters were fresh, but com- 
municated with the sea; the conditions were apparently those of a deep estuary, into 
which fresh-water streams ran, and in these rivers lived the crayfish. The deposits were 
probably Eocene, if these divisions are to be retained for the Tertiary deposits of the 
West, and may have been laid down nearer the ocean than those of Green River.” 
In 1870 Cope§ described three extinct species of Astacus from fresh-water Tertiary 
deposits in the Territory of Idaho. The specimens were obtained by Clarence King, on 
the expedition sent out for the geological exploration of the fortieth parallel west of the 
Mississippi River. I have not been able to find the specimens in the Smithsonian Insti- 
tution, where they belong. 
The first species described by Cope is named Astacus subgrundialis. In this form 
the rostrum is narrow, concave above, acute, with five spinous points on each side and 
a terminal recurved spinelet; two post-orbital tubercles on each side, the anterior pair 
spiniform ; surface of the carapace smooth or obsoletely wrinkled ; abdominal pleura promi- 
nent and acuminate, those of the second segment four times as wide as the others; chele 
nearly smooth, not granulate, the superior edge spiniferous ; the longitudinal groove of the 
carpus is well marked, and this segment is not spiniferous; the antennal scales are large, 
and extend nearly to the tip of the rostrum; areola of moderate width. Length to cervical 
* Neue Fische und Krebse aus der Kreide von Westphalen. Von Dr. W. von der Marck und Dr. Cl. 
Schliiter. Palaeontographica, XV. 302, Taf. XLIV. figs. 4, 5, 1868. 
+ So also with the genus Astacodes founded by Bell (Mon. Foss. Malacostr. Crust. Great Britain, Pt. 
IL. Crust. of the Gault and Greensand, p. 30, Pl. IX. figs. 1-6, 1862) for the reception of Meyeria faleifer 
Phillips from the Speeton Clay. 
+ “Fossil Crawfish from the Tertiaries of Wyoming,” Amer. Nat., XIV. 222, 223, Mareh, 1880. “On 
a Crayfish from the Lower Tertiary Beds of Western Wyoming,” Bull. U.S. Geolog. and Geograph. Sury. 
Terr., VI. 391-397, with two cuts, September, 1881. 
§ “On Three Extinct Astaci from the Fresh-water Tertiary of Idaho,” Proc. Amer. Philosoph. Soe., 
XI. 605-607, 1870. 
