70 CALIFORNIA ACADEMY OF SCIENCES. 



carapace is furnished with four prominent triangular teeth including the 

 postorbital and the one at the lateral angle; the posterior margins of these 

 teeth are armed with several denticles and the three anterior teeth have 

 each two denticles on the anterior margin; the fourth tooth has three 

 nearly equally spaced denticles on the inner side of its anterior margin 

 and a fourth at a longer interval from the others near the tip. Postero- 

 lateral margin with two teeth. Body and appendages strongly setose. 

 Length of carapace, 50 mm.; breadth, 64 mm. 



Northeastern Siberia, Aleutian Islands, Behring Sea, 

 Sitka, Vancouver's Island, Puget Sound, upper Cali- 

 fornia. 



There is a specimen in the museum of the University 

 of California labelled Gulf of California, but possibly 

 this is wrong, as this species appears to be a northern 

 one. This species may be distinguished from T. acuti- 

 dens by its broader carapace, its larger and broader lat- 

 eral teeth and by the median teeth of the front. For a 

 fuller list of localities and other facts concerning this 

 peculiar species see Benedict 1. c, pp. 224-227. 



Section PORTUNINEA Ortmann. 



Carapace more or less rounded, with the antero-lateral margin sharply 

 marked off from the postero-lateral. The last pair of thoracic legs fitted 

 for swimming. Verges of the male in the coxae. 



Genus Portunus Fahr. 



Carapace usually transverse, depressed, and marked with granulated 

 lines. Front short and cut into five to eight teeth. Antero-lateral mar- 

 gins arcuated and armed with nine teeth, all but the last (the largest) 

 being of subequal size. Flagellum occupying the inner orbital hiatus. 

 Merus of the chelipeds armed with spines on the inner margin; hand 

 elongated, prismatic and costate. 



Type. — P. pelagicus (Linn.). 



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