l6 TRUE CRABS OF MONTEREY BAY 



comes indistinct. The lateral margins of the cardiac region anterior to 

 the cervical groove are marked by distinct sulci, external to which are low 

 elevations, the anterior border is marked by a much less definite sulcus 

 concave in front. In the type (male) which was carrying what was ap- 

 parently a sand-encrusted ascidian, nearly all of the carapace lateral and 

 posterior to the cervical groove, with the exception of the intestinal region, 

 is membranaceous ; while in the second specimen, a female, only the sub- 

 branchial region is uncalcified. 



Antennae prominent, the basal portion four-jointed, the basal joint 

 wider than long, the green gland opening at its inner margin between two 

 acute inwardly projecting tubercles, the second joint the longest, project- 

 ing far enough to be slightly visible from above, the last two joints small, 

 subequal, inserted in a deep rounded notch in the antero-internal angle of 

 the preceding joint, the flagellum sparingly ciliated, more than half the 

 length of the carapace. Lower orbital margin ending in a prominent ob- 

 tuse tooth next the basal portion of the antennae. Basal joint of the anten- 

 nule large, reaching about to insertion of last two joints of the antenna, 

 last two joints subequal ; the last with two unequal brushes of hairs at the 

 tip; in the normal position the last two joints are almost entirely concealed. 



Endostome with a low ridge on either side bounding the efferent 

 branchial channels. External maxillipeds stout, the ischium slightly wider 

 at the distal end and armed on the inner margin with a row of 7 or 8 

 conical, corneous-tipped spines, the merus rectangular, slightly shorter 

 than the ischium, distally truncated, very slightly rounded, both corners 

 square. Palp articulated to inner side of merus near tip, entirely visible 

 when in normal position ; exognath nearly reaching tip of merus, tapering 

 but little. 



Chelipeds hairy except tips of fingers, stout, ischium small without 

 prominent armature, merus trigonal, all the angles denticulated, a wide 

 transverse sulcus above paralleling the distal margin, carpus short and 

 stout, denticulated at anterior angles, hand without any conspicuous spines 

 or tubercles. In these characters it does not differ widely from Stimpson's 

 description of D. antillensis. The tips of the fingers are calcareous, of a 

 light flesh color, markedly excavated at the tip and armed with large tri- 

 angular teeth which interlock at the tip but gape pronouncedly at the base. 



Ambulatory legs hairy, less stout than chelipeds but hardly "slender" 

 as in D. antillensis. The last pair are unfortunately missing in both spec- 

 imens ; of those remaining the first and second are the largest and differ 

 little in size, they are unarmed with the exception of the dactyls which 

 terminate in strong, curved, corneous spines and are further armed with 

 three or four straight corneous spines on the lower margin. The third 



