114 CALIFORNIA ACADEMY OF SCIENCES. 



Body and legs much flattened and densely covered with short hair. 

 Carapace subcordate, nearly smooth, but roughened or granulated at the 

 insertions of the hairs. Front short, acute, narrowly triangular. Post- 

 orbital tooth large, acute, and extending nearly as far forward as the front. 

 Superior orbital margin concave and furnished with a small, acute tooth 

 which is separated from the postorbital by a deep fissure. The portion of 

 the antero-lateral margin in front of the cervical groove is convex, sub- 

 laminate, edentate, and separated from the portion behind the groove by 

 an incision; two marginal teeth at the origin of the sutures. Ocular 

 peduncles short, hairy, and swollen at the base, where they are furnished 

 with a small, smooth tubercle. Antennas about as long as the carapace; 

 acicle ovate, acute, very thin, more or less transparent, and margined by 

 hairs on both sides; a smooth, slender spine joined beneath, and reaching 

 nearly to the tip of the acicle. Second joint of the palp of the maxillipeds 

 with a rounded inner lobe; last joint rounded distally and somewhat flat- 

 tened. Chelipeds flattened, not tuberculated, anterior margin of the merus 

 produced and cut into two teeth; carpus produced into a tooth at the pos- 

 tero-distal angle and bearing a single spine at the proximal end of the 

 anterior margin; larger hand with one or more small, calcareous tubercles 

 on inner face behind the articulation of the .dactyl; inner margin of the 

 smaller hand produced into a rounded lobe behind the base of the dactyl; 

 the fingers of the smaller hand are excavated within, the edges corneous 

 and armed with small, calcareous denticles. Ambulatory legs much flat- 

 tened and very hairy, the anterior margins deeply incised, forming four or 

 five closely approximated teeth on each of the larger joints; postero-distal 

 angle of the carpi produced into a tooth or lobe which is very prominent 

 on the third pair; dactyls short, flattened, the curved, corneous tips 

 turned obliquely to the plane of compression. The abdomen is broad and 

 bent abruptly at about the third segment, the reflexed portion not so 

 hairy as the upper side; the calcareous plates on the basal segment are 

 wide and separated by a membranous interval in which there is no median 

 plate. In the female the left side of the abdomen is coriaceous and seg- 

 meutally incised. 



Length of carapace from tip of rostrum, 17 mm; breadth, 19 mm.; length 

 of large hand, 28 mm.; length of small hand, 20 mm. 



Northern to southern California! Monterey (Stimp- 

 son)! Found under rocks at low tide. Common. 



