30 BULLETIN OF THE 



has a central circular depressed area ; the succeeding pleura decrease regularly 

 in size posteriorly, scarcely overlap when the abdomen is extended, are convex 

 in outline posteriorly but straight or slightly concave anteriorly, and the third, 

 fourth, and fifth are ornamented with a median curved carina extending two 

 thirds of the length, but not well marked upon the fifth. 



The telson is pretty regularly triangular, about twice as long as broad, is 

 convex and slightly grooved longitudinally above, and terminates in an acutely 

 rounded tip unarmed with spines. The lamella3 of the uropods scarcely reach 

 the tip of the telson : the outer is nearly as broad as long, regularly rounded 

 in outline except for a'short distance on the outer edge near the tip, where the 

 margin is more or less conspicuously truncated, but varying considerably in 

 different individuals, and stiffened by two slightly diverging ribs in addition 

 to the thickening of the outer margin ; the inner lamella is stiffened by a single 

 median rib, is nearly twice as long as broad, the lateral margins are approxi- 

 mately straight and parallel, and the tip is regularly rounded in outline. 



In the male the first pair of abdominal appendages (PL IV. fig. 14) are much 

 longer than the protopods of the second pair, reach slightly beyond the bases 

 of the fourth thoracic legs, and have an imperfect articulation at about a third 

 of the way from the base to the tip ; the basal portion is somewhat triquetral, 

 while the terminal expands into a smooth, naked, and thin lanceolate lamella 

 slightly concave posteriorly. The second pair reach slightly farther forward 

 than the first, and the protopod and lamellae are about equal in length. The 

 lamellae are narrow, lanceolate, and thickly ciliated along the edges ; the inner 

 is about as long as the outer, and bears the two styliform processes usually 

 characteristic of males in the Macrura. These styliform processes are a little 

 less than a third as long as the lamella itself, and arise together at about a third 

 of the way from the base to the tip of the lamella ; the inner, like that upon 

 the three succeeding pairs of appendages, arises from the slightly thickened 

 inner edge of the lamella, is ridged, of nearly equal width to the rounded tip, 

 and nearly naked except a line of cilia along the posterior margin. The outer 

 process arises just in front of the inner, and its base is at a right angle to that 

 of the outer ; it is more slender than the outer, tapers distally, and is ciliated 

 on both edges and on the anterior surface. The three succeeding pairs of 

 appendages are similar to the second pair, but the fourth and fifth pairs are 

 successively a little shorter, and, as usual among Macrura, they all want the 

 outer of the two styliform processes of the inner margin of the inner lamella. 



In the female the first pair of abdominal appendages (PI. IV. fig. 13) are 

 about as long as in the male ; the basal portion, or protopod, is scarcely more 

 than half as long as the terminal lamella, is narrow, compressed, turned inward 

 toward the mesial line, and clothed thickly along the outer and the distal part 

 of the inner edge with long ovigerous hairs ; the terminal lamella is multi- 

 articulate, like the lamellse of succeeding appendages, but a little narrower than 

 they, and is clothed with numerous ovigerous hairs. The four succeeding 

 pairs of appendages are very nearly like the three last pairs in the male, but the 

 styliform process of the inner lamella is a little larger and more compressed. 



