Boone, Crustacea, Cruise of ''Alva," 1931 173 



with the under surface wide, flat, with an irregular, laminate 

 angulation at its inferior subdistal angle ; both lateral surfaces 

 of the merus are narrowed, each being less than the one-third of 

 the width of the lower surface ; the upper surface is similar to the 

 lower, except that it lacks a distal angulation ; the carpus is small, 

 obconic, hinge-like, sharply excavated on the inner lateral surface 

 and with the distal margin concavely excavate; the palm is 6 

 millimeters long, including the fingers, the fingers being one-third 

 of this length. The palm is dilated and dorsally convex for the 

 proximal three-fifths, attaining its greatest width, which is one- 

 third of the length, at this point, beyond which the distal two- 

 fifths of the palm, fingers not included, is somewhat compressed 

 laterally, this becoming more decided toward the area adjacent 

 to the base of the fixed finger. This fixed finger is dorsal in po- 

 sition, one-third of the length of the palm, or one-fourth of the 

 total propodal-dactylar length, and is slender, tapered, much com- 

 pressed laterally, with a decidedly curved, acuminate tip, overlap- 

 ping that of the opposed finger; the cutting edge is proximally 

 bidentate, distally laminate on the inner surface, and this is 

 paralleled on the outer side by a distinct, narrow, concave trough, 

 or groove, which is deepest near the tip. Several long, solitary 

 setae are present within this groove ; also both fingers have nu- 

 merous long, solitary setae fringing both the upper and lower outer 

 lateral margins. The hinged finger, which is curiously ventral in 

 position, has a decidedlj^' curved, acuminate tip. This finger is 

 approximately as strong, wide and deep as the lower finger. The 

 hinged finger is wider proximally, transversely depressed at the 

 base, thence angulato-sinuate in dorsal profile, also in lateral pro- 

 file ; viewed dorsally the proximal two-fifths is somewhat com- 

 pressed laterally, with a decided blunt node two-fifths of the 

 length from base, accentuating the point at which the distal three- 

 fifths of the finger abruptly curves inward; this distal portion 

 is widened, low, rounded dorsally, its outer lateral margin 

 quite convex, subcarinate, the inner lateral margin less convex, 

 both converging distally toward a medial rounded node above the 

 base of the down-curved, laterally compressed, medially carinate, 

 acuminate tip, which fits into and overlaps slightly beyond the 

 concavity of the fixed finger ; the cutting edge of the fixed finger is 

 produced into a thin lamina which forms a triangulate tooth proxi- 

 mally that fits in between the two similar teeth of the lower finger. 



