584 PROCEEDINGS OF THE NATIONAL MUSEUM. vm.. xxvm. 



joint, veiT stout, and furnished with a short accossorv spine on the 

 ventral surface (tio-. io(J). 



This claw is operated by powerful nuiscles contained in the basal 

 joint and it must make an oti'ective prehensile organ. 



Furca lon^and narrow, the l)ase longer than the branches, the latter 

 of a bi'oad U-shape with the sides nearly parallel. 



The first thoracic legs are so small and weak as to appear shriveled; 

 this is especially noticeable in the plumose sette along- the posterior 

 margin of the terminal joint, which are scarcely longer than the diam- 

 eter of the joint. In the alcoholic specimen taken from the menhaden 

 tin; two ])osterior of the three terminal claws are branched, the 

 branches being straight, longer than the tips of the claws, and 

 inserted nearly at right angles to the axis of the claw (fig-. lo3). In 

 the living specimens obtained by the author from the sword-lisli the 

 claws are mostly unbranched, but are of the same relative size as in 

 the menhaden specimen. 



In all the specimens the appendage at the inner corner of the joint 

 is a long, strongly curved claw instead of a plumose seta. 



riiis is similar to the condition in sfJust(>ii;/.i\ but the relative size of 

 the claws and the seta is entirely ditierent in the two species. The 

 second legs are large, of normal structure, and armed with long acumi- 

 nate spines. The rami of the third leg's are well separated, the chiw 

 on the ])asal joint of the exopod is large and slightly curved, while 

 the endopod is one-jointed. 



The fourth legs are three-jointed, long and slender, the basal joint 

 as long as the other two. This leg carries live spines, one at the 

 distal end of the second joint, one on the outer mai'gin of the terminal 

 joint and three at the end. 



Of the latter the inner one is al)out twice as long- as the outer. 



The fifth leg's are not visible dorsally. 



Total length in menhaden specimen 5 mm. Length of carapace 2.5 

 nun. ; width of same 2.1 mm. ; length of genital segment 1 mm. ; length 

 of al)domen l.-i mm. 



Total length of swordtish specimens 6-().5 mm. Length of carapace 

 3 mm.; width of same 2.3 nmi.; length of g-enital segment 1.(5 mm.; 

 length of abdomen 1.45 mm.; length of egg strings 3.2 mm.; 45 or 50 

 eggs in each. 



Color a ti'ansparent yellow, very thickly spotted on both the dorsal 

 and ventral surfaces with })ranching pigment dots of a rust}' brown. 

 These spots are (juite similar to those on (\ rapax in shape and 

 arrangement, but the resultant color is a sober g'ra}' ))rowm quite 

 dirt'erentfrom the bright red tint of rapax. In fact, there is enough 

 difference in the color alone to distinguish the two species when taken 

 together on the swordtish. 



