CRUSTACEA. 
197 
Distribution. This species is represented in the collection of the State 
Museum by fifteen specimens, most of which are in a very fragmentary condi¬ 
tion, on account of the fragility of the test. In one locality, at the lower falls 
of Vinegar Brook Glen, near Norton’s Landing, on Cayuga Lake, individuals 
have proven to be quite abundant in the shales, but are so massed together and 
macerated as to be unsatisfactory for purposes of description. Hamilton group. 
In the shales at Tichenor’s Glen, Canandaigua Lake; near Norton’s Landing, 
Cayuga Lake, and upon the shores of Owasco Lake. 
Rhinocaris scaphoptera, n. sp. 
PLATE XXXI, FIGS, ii, 23. 
Cephalothorax elongate, outline as in Tropidocaris. The prora at the anterior 
extremity is shorter than in the foregoing species, is vertically flattened and 
narrowly lanceolate, slightly broadened on its upper edge toward the base. 
The margin curves rapidly backward from the base of the prora to the ven¬ 
tral edge, thence slightly upward to the posterior margin, which is transverse 
and somewhat incurved over the dorsum. The single specimen of this species 
which has been observed, is folded unsymetrically along the dorsum, and is 
laterally compressed. There are indications of a faint ridge in the axial 
line of the carapace, but this part has been broken along one side of that line. 
A strong lateral carina beginning near the anterior extremity is nearly paral¬ 
lel to the ventral margin, and becomes obsolete in the posterior region. Just 
above its anterior extremity on each side is a low elevation, which is prob¬ 
ably an optic node. 
The Surface is ornamented, on the lateral regions below the carina, with 
elevated lines parallel to the ventral margin, which are stronger and more 
frequently interrupted than in Rhinocaris columhina. The surface of the 
median area within the carinoe, bears elongate linear nodes parallel to the 
axis, and several of these are visible over the surface of the optic spot. The 
intermediate space between the lines and nodes is minutely punctate. The 
