Boone, Crustacea, Cruises of ''Eagle" and "Ara," 1921-28 111 



Type: Latreille's type came from "Nouvelle Holland" (old name 

 for Tobago and St. Martin's, W. I.), and is deposited in the National 

 Museum d'Histoire Naturelle, Paris. 



Distribution: Known sparingly from Beaufort, N, C, to Miami, 

 Florida, and more abundantly in southern Florida, the Bermudas, 

 Bahamas, and West Indies, southward to Desterro, Brazil, in depths 

 ranging from the tide-line to 40 fms., more abundant in shallow water. 

 Latreille's type locality, Nouvelle Holland, translated in present-day 

 geographic terms would be either Dutch Guiana, St. Eustace, St. 

 Martin's or Tobago, W. I. 



Material examined: One female taken at Pigeon Key, Florida, 

 April 17, 1923. One male taken at Hogsty Island, San Salvador, 

 Feb., 1926. Two large males taken in dragnet, Cardenas, Cuba, 

 March 5, 1928. 



Habits: This is the ''grass crab" of the early British Colonial 

 naturalists, a name derived from the fact that hicornutus clothes itself 

 with seaweed, sponges, etc., as a camouflage to protect it from its 

 enemies. 



Technical description: Carapace subtriangular, with rostral 

 horns slightly more than one-third as long as the rest of the body; 

 carapace rather tumid posteriorly, the anterolateral angles far back 

 and produced into a spine. The upper surface of the carapace is 

 rough; the cervical and urogastric grooves deeply delineated; there 

 are several prominent tubercles on the elevated part of the gastric 

 region; the cardiac region has four or five; there are several on the 

 more elevated parts of the branchial region, and four to six form an 

 arc on the intestinal region. Numerous hook-like setae are scattered 

 over the carapace. The rostral horns are triangular, flattish on the 

 upper surface, divergent throughout their length, except that occa- 

 sional young specimens have the tips incurved. The basal antennal 

 segment has a flat, obtuse spine at the anterior angle, which is dorsally 

 visible as a knob-like projection ; behind this spine on the margin is a 

 small spine. The first and second free articles of the antennae are 

 subequal in length, lie beside the rostrum, extending half its length ; 

 the flagellum is multiarticulate, reaching beyond the rostrum for a 

 distance equal to the length of the rostrum. The preorbital angle is 

 blunt, nearly right-angled. The postorbital angle is also blunted. The 

 cornea is prominent and never covered by the sponges, etc., beneath 

 which the crab conceals itself. 



