with Miss Rathbun's description in having no accessory spines on the rostrum; the superocular eave thick, projecting at its posterior angle into a sharp tooth; the post-ocular spine simple; in having two spines on the posterior margin of the carapace; and in most of the other characters. The carapace, however, appears smoother than in Miss Rathbun's specimens, and in the central part the spines mentioned by her are either absent altogether or indicated only by slight tubercles; the two cardiac spines and the intestinal spine are thus indicated in some specimens, but there seems no indication whatever of the three gastric spines. My largest specimen has the carapace from the tip of the rostral spines to the extremity of the spines on the posterior margin 17 mm. in length, and the width without spines 10 mm., thus corresponding with the dimensions given by Miss Rathbun. Her specimens are from the Hawaiian Islands.