MAIOPSIS PANAMENSIS. 13 



Maiopsis panamensis Fax. 



Plate II. 



Bull. Mus. Comp, Zool,, XXIV. 151, 1S93. 



Carapace subtriangular, as broad as long, convex, the anterior gastric 

 region sloping rather abruptly down to the ba.se 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 

 dor.sal surface of the carapace is thickly set with spines of various sizes, and 

 scattered hooked seta? ; 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 the.se 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 anotlier 

 closely at the anterior end of the cardiac area. The basal segment of the 

 antennte 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 tubei'cle. 



The legs are long, and covered with numerous spiny tubercles ; the 

 raeri 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 dor.sal 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.; 



