204 
PALEONTOLOGY OF NEW YORK. 
elevated grooved line riuis backward, bifurcating once and becoming extinct 
before reaching the middle of the shield. 
The eyes are wanting, but the sockets of the ocular peduncles are plainly 
discerned. The antennules are absent, the antennae being represented by 
two very long and large joints, which are flat on their lower surface, convex 
above and somewhat inflated in the middle; their inner extremities are 
concealed beneath the cephalothorax, but they are undoubtedly the distal 
peduncular joints of these appendages similar to those in some species of 
Crangon {C. boreas). A single joint of a maxillary palpus {^.) is visible on the 
right side of the specimen, followed by portions of all the five pairs of 
ambulatory appendages. Of the first leg two joints are visible, the proximal 
being very broad where it disappears beneath the carapace, tapering to a 
narrow anterior extremity; the distal joint is also broad, but narrower than 
the former; the second leg is indistinctly represented by fragments of two 
joints, both of which appear to have been slender; the third leg shows two 
joints, the proximal broad and the distal more slender; the fourth is repre¬ 
sented by a single slender inner joint, while the fifth shows three joints, all of 
which are very slender. 
The ABDOMEN tapers rapidly toward the telson, the somites increasing in length 
as they grow narrower. The somites are strongly arched, the ventro-lateral 
portions being somewhat incurved and posteriorly inclined. The basal joint 
of the first two abdominal appendages on the right side, and of the second 
and third pair on the left side are visible. The surface of the somite, 
though indistinctly preserved, was evidently ornamented as in the 
cephalothorax. 
The TELSON consists of a broad, rapidly tapering, convex spine, bearing a low 
axial ridge ; articulated to its antero-lateral margins and to the posterior mar¬ 
gin of the ultimate somite are the compound lateral spines, which are con¬ 
nected by a membranous expansion. The lateral caudal spines are com¬ 
posed of a short basal joint, sub-pentagonal in outline, the anterior margin of 
which is articulated to the ultimate somite, the outer posterior margin being 
