MAIOPSIS PANAMENSIS. 13 
Maiopsis panamensis Fax. 
Plate I. 
Bull. Mus. Comp. Zool., XXIV. 151, 1893. 
Carapace subtriangular, as broad as long, convex, the anterior gastric 
region sloping rather abruptly down to the base of the rostrum, which is 
split about half way down to the front into two divergent horns; each ros- 
tral horn is armed with a stout basal spine directed upward and forward. The 
dorsal surface of the carapace is thickly set with spines of various sizes, and 
scattered hooked set ; the largest spines are arranged as follows: five on 
the gastric region (three in the median line and two lateral), one on the geni- 
tal region, one on the cardiac region, four (three of which are submarginal) 
on the intestinal region, and about seven on each branchial region. The 
margin of the carapace is armed with about twelve prominent spines; three 
of these are on the hepatic region ; the posterior one is much smaller than 
the two in front of it, which are confluent at their bases. The superior mar- 
gin of the orbit is deeply cut by two open fissures; the eyebrow is armed 
with two stout spines. The branchio-cardiac lines approach one another 
closely at the anterior end of the cardiac area. The basal segment of the 
antenn is very broad; its distal margin is armed with a strong internal 
spine directed downward and forward; a second spine, pointing obliquely 
forward, arises from the external angle ; while a third bifid spine lies between 
the other two; there are, besides, a few spinules on the lower side of this 
segment. The anterior margin of the third segment of the outer maxillipeds 
is denticulate. The sternum is ornamented with small tubercles along each 
side of the abdomen. ‘The first abdominal segment is furnished with a 
bidentate tubercle. 
The legs are long, and covered with numerous spiny tubercles; the 
meri are armed with three more prominent spines at the distal end. The 
first ambulatory leg is the longest, the others decreasing in length successively 
from before backward. The carpus of all the four pairs of ambulatory 
appendages is marked with a dorsal longitudinal groove. The chela is long 
and slender, the tubercles on the hand smaller than on the other parts of the 
legs, while the fingers are nearly smooth, subcanaliculate, and blunt-tipped ; 
a deep pit is seen at the base of the movable finger. 
Length from base of rostrum to posterior margin of carapace, 112 mm. ; 
