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Bulletin, Vanderhilt Marine Museum, Vol. II 



region and one or two especially prominent rugae crossing tlie anterior 

 intestinal region. The frontal margin is trilobate, the median lobe 

 being the wider, its margin regularly convex and evenly dentate ; the 

 submedian teeth are not quite as protruding as the median and have 

 the inner side shorter than the outer, which is curved out continuous 

 with the almost right-angled preorbital angle, and regularly dentate. 

 The superior orbital margin is crenulate or dentate and has two 

 straight sinuses. There is one sinus on the inferior orbital margin, 

 and it is also dentate; the infraorbital angle is right-angled, promi- 

 nent but wide apart from the superior margin. The anterolateral 

 margin is rounded, cut into five sharp, forward-directed teeth, includ- 

 ing the preorbital tooth. Of these, the first and second teeth are sub- 

 equal, slightly smaller than the third and fourth teeth, which are also 

 subequal and have the postlateral side more convex ; the fifth tooth is 

 the smallest of the series but is well developed, acute and directed 

 more sharply upward. The postlateral margins are convergent, exca- 

 vate; the posterior margin is narrow, straight. The male abdominal 

 belt is five-segmented ; the first and second segments are narrow, with 

 a transverse median ridge; the third, fourth and fifth segments are 

 fused, with two transverse carinae; the sixth segment is narrowed 

 distally; the seventh segment is triangulate. The sternal plastron is 

 hirsute and has many transverse rugae. The pterygostomian region 

 is hirsute and has many rugae. 



The external maxillipeds are finely setose on the outer surface and 

 have the exognath long, slender; the ischium subrectangular, with a 

 deep, submedian longitudinal groove on the outer face; the merus is 

 squarish, with the inner lateral angle broadly truncated for the recep- 

 tion of the palp. 



The antennulae have the basal joint large, the free joints very 

 slender, folding transversely. 



The antennae has the basal article produced on its outer distal side 

 into a flaring rounded lobe that occupies the wide infraorbital fissure ; 

 the second and third articles are successively slenderer ; the flagellum 

 consists of about 38 articles. 



The eyestalk is short, densely setose; the cornea is shining black, 

 spherical, composed of many fine facets. 



The chelipeds are slightly unequal in the male, short; the merus 

 three-sided, its under face especially marked by diagonally transverse 

 rugae; the carpus is convex, dorsally produced on the inner lateral 

 margin to an acute, broad, triangulate tooth ; the upper surface covered 



