Boone, Crustacea, Cruise of "Alva," 1931 179 



acute spine at the inferior outer distal angle; the carpus short, 

 cup-like, distally concave with a bidentate process at the upper, 

 outer distal angle ; the palm, which is 11 mm. long, or a little over 

 twice as long as the carapace, the fingers being one-third of this 

 total length, 3.8 mm. long, lies so that the chela opens horizontally, 

 with the hinged, upper finger lying on the outer side, instead of 

 the usual upper position. The palm, which is convex proximally 

 and which is substantially dilated for the proximal two-thirds of 

 the length, is subcylindrical, being one-half as high in the greatest 

 height as long, and approximately two-thirds as thick as high, 

 tapers distally towards the base of the finger, where it terminates 

 in a blunt, low node on the upper outer side, this upper outer mar- 

 gin appearing in profile, to terminate in a small denticle. The 

 lower finger, which is laterally compressed, bears proximally a 

 large, obliquely placed, rounded molar that fits into an opposed, 

 deep concavity of the upper finger ; beyond this molar the lower 

 finger is abruptly compressed, the cutting edge becoming a lami- 

 nate convexity, the tip being upcurved, acuminate, overlapping 

 that of the upper finger. The inner, or upper side of this outer 

 laminate cutting edge is paralleled by a linear but definite chan- 

 nel. There is on the inner (exposed as upper) surface a curved, 

 shallow suture line that proximally appears about two-fifths of 

 the length of palm from base, curves down on the inner surface 

 to extend more than half the depth of the palm and thence 

 up and forward, vanishing on the anterior margin of the palm 

 above base of fingers. This suture is continuous thence on the 

 outer (lower) surface of the palm, which is less arched, extending 

 only the upper third of the depth of the palm and completing an 

 elliptical outline. All surfaces of the cheliped and ambulatories 

 are furnished with numerous solitary hooked setae. The upper 

 finger is sublunate in outline, with the upper margin very convex, 

 the cutting edge proximally with a deep concavity and beyond this 

 sinuate, terminating in an acute tip that overlaps on the upper 

 side of the lower finger. 



The ambulatories are moderately stout, successively decreas- 

 ing in length in the order 1, 2, 3, but subsimilar, with the merus, 

 carpus and propodus subcylindrical, laterally compressed ; the 

 dactyl short, blunt, with substantial thickened base which is sub- 

 triangulate and corrugate on the basal (ventral) surface, the 

 apex blunt ; with the upper surface rounded, thickened and sup- 



