364 PALEOZOIC PALEONTOLOGY. 
CEPHALOPODA. 
ORTHOCERAS sp. undet. 
A single fragmentary specimen, which is probably the cast of a 
portion of the chamber of habitation of a species of Orthoceras, has 
been observed in the Orbiculoidea jervensis fauna. 
ARTHROPODA. 
TRILOBITA. 
DALMANITES sp. undet. 
Plate) i. Wigs) G: 
A few more or less fragmentary specimens of the pygidia of Dal- 
manites have been observed in the Oriskany fauna of New Jersey. 
These specimens may represent more than one species, but they are 
too imperfect for identification, especially in the absence of any of the 
cephalic characters. The most nearly-perfect specimen is a large pygi- 
dium from near the New York State line, north of the Nearpass sec- 
tion, and, when complete, the specimen must have had a length of 
nearly 60 mm. and a width of over 70 mm. The axis is rather narrow, 
subangular along its median line, bending upward posteriorly, and 
is composed of more than twenty segments. The posterior extremity 
is broken, so it is not certain whether it was produced as a spine or 
not. The pleural slopes are rather regularly convex and are marked 
by about sixteen segments. 
PHACOPS? sp. undet. 
Plate: G5 Hise 7: 
A single imperfect pygidium may represent a species of this genus, 
but it is too imperfect for certain identification. 
