238 University of California Publications in Zoology [Vol. 23 



they are separated from, each other; inner supraorbital fissure more or less closed; 

 postorbital tooth extends nearly as far forward as the teeth of the front. Carpus 

 of ehelipeds with several granulated ridges on the outer surface, a strong spine at 

 the distal end of upper margin, and a smaller one on lower side, at distal end of 

 lowest granulated ridge; hand with a spine at external hinge joint, the granulated 

 ridge on the upper margin terminating in a spine a little behind the distal end of 

 the palm ; there are four granulated ridges on the outer surface of hand, not count- 

 ing the upper one; fingers strongly and distinctly ridged on outer face. 



Dimensions. — Type, female: length of carapace 13.7 mm., width 26.7 mm. Of 

 male: length of carapace 25.25 mm., width 53 mm. (Holmes). 



Type Locality. — Cape St. Lucas, Lower California, common on the beaches. 



Distribution. — From Puget Sound to Chile. Except for a single specimen 

 taken by the ' ' Albatross ' ' in Puget Sound, this species is not known north of 

 Santa Monica Bay, California. It almost seems that the Puget Sound record 

 is the result of an incorrect label. 



Family Xanthidae (Pilumnidae) 



Carapace more or less transversely oval; front moderately broad, often toothed, 

 in the latter case always with a median notch; anterolateral margins arcuate, and 

 armed with several lobes, teeth or spines. Antennules fold back transversely or 

 obliquely. Fingers of ehelipeds more or less curved. 



Key to the California Genera of the Xanthidae 



I. The ridges that define the efferent branchial channels, if present, are low and 

 are confined to the posterior part of the endostome, never reaching the 

 anterior part of the buccal cavern. 



A. Fronto-orbital border less than half the greatest width of the carapace. 



(Not known north of San Pedro.) 



Cycloxanthops, p. 239. 



B. Fronto-orbital border half or more than half the greatest width of the 



carapace. 



1. Carpal joints of ambulatory legs armed above with a horned or 



lunate crest. (Not known north of San Diego.) 



Heteractaea, p. 248. 



2. Carpal joints of ambulatory legs not armed with a horned crest. 



a. Carapace transversely oval; front divided by an open, rounded 



notch. Ambulatory legs devoid of a crest on upper margin. 



(Not known north of Monterey.) 



v Xanthias, p. 245. 



b. Carapace more or less hexagonal or subquadrate; front divided 



by a more or less closed fissure. Ambulatory legs with carpal 

 and propodal joints more or less cristate. 



Lophopanopeus, p. 240. 



II. The ridges that define the efferent branchial channels extend to the anterior 



boundary of the buccal cavern and are often very strong. Fronto-orbital 



border much more than half the greatest width of carapace. Ambulatory 



legs not carinated. (Not known north of Venice.) 

 to v Pilumnus, p. 247. 



