Boone, Crustacea, Cruises of '^ Eagle" and "Ara," 1921-28 173 



by a wide, shallow sinus from the preorbital teeth, which are bluntly 

 rounded and not quite 'as long as the lateral teeth and are weakly 

 bidentate. The infraorbital tooth is broad, obtusely rounded, very 

 prominent dorsally. There are eight teeth, including the preorbital, 

 on the anterolateral margin; of these the anterior four are wider 

 basally and, although acute, they are less acuminate than the posterior 

 four; the ninth or lateral spine is very slender, pointed outward and 

 upward and is as long as one-third of the distance between the bases 

 of these spines. The upper surface is obscurely granulate and hairy ; 

 the cervical and urogastric grooves are well defined; there is a fine, 

 granular ridge curving in from the lateral tooth upon the branchial 

 region. The female abdominal belt is subcircular, the distal joint 

 abruptly smaller, triangulate. The male belt is narrowly triangulate, 

 five-segmented, the third segment with a sharp median transverse 

 carina. 



The external maxillipeds have the ischium short, its inner lateral 

 margin broadly convex, the distal margin excavate, with the outer 

 margin subacute ; the merus is set obliquely, slightly higher than wide, 

 with the angles rounded, the distal margin convex; the inner angle 

 scarcely at all excavated for the palp. 



The antennulae are very slender and fold transversely. 



The antennae have the basal peduncular joint produced into an 

 elongate, rounded lobe at its lower distal angle ; the second and third 

 articles are short, cylindrical ; the flagellum consists of about twenty- 

 five short articles. 



The eyes are large, reniform, filling the orbital cavity. 



The chelipeds are very long and slender; in old males from six to 

 seven times the length of the carapace; there is one spine at the tip 

 of the inner lateral margin of the ischium; four, occasionally five, 

 spines on the inner margin of the merus, one quite long at the pos- 

 terior distal angle of the merus; the carpus is elongate, half as long 

 as the palm, with several light longitudinal ridges of granulae; a 

 sharp spine at each the outer and inner distal angles ; the palm is very 

 slender, with five longitudinal ridges on the outer face ; the uppermost 

 ridge forms the margin and terminates subdistally in a spine; there 

 is also a spine at the base of the third carina, adjacent to the carpus ; 

 the fingers are exceedingly slender, slightly longer than the palm, 

 groove on the outer face and set with stocky, triangular teeth. 



The ambulatories are very slender, the propodi and dactyli sub- 

 equal, grooved, the inner lateral margins fringed with setae. 



