252 



BULLETIN 129^ UNITED STATES NATIONAL MUSEUM 



British Columbia (lat. 52° 39' 30" N.) southward to Oregon (lat. 

 43° or 00" N.). Depth, 49 to 1,625 fathoms. 

 Material examined. — See table, page 251. 



Genus HYAS Leach 



Hyas Leach, Edin. Encyc, vol. 7, 1814, p. 431; type, H. araneus (Linnaeus). 



Carapace broad, but still narrower than the postfrontal length, 

 more or less lyrate or shield-shaped, tuberculate and pubescent. 

 Rostrum triangular, flat, bifid, horns separated by a narrow slit or 

 interspace. Eyes when retracted not entirely covered by the narrow 

 supraocular eave; a fissure above and below the orbit; postocular 

 cup formed by a large, triangular, flattened and acute tooth. A 



Fig. 90.— Htas, left basal antennal article of three species, a. araneus, male (10031). 



6. COARCTATUS ALUTACEUS, male (40182). C. LYRATUS, MALE (15927) 



tubercle on the middle of the anterior surface of the eyestalk. Basal 

 antennal article of good size, longer than wide; the next, or first 

 movable, article laterally dilated; last article of peduncle, narrow, 

 cylindrical. Chelipeds stout, chelae compressed. Ambulatory legs 

 subcylindrical. 



Distribution. — Arctic Ocean with the exception of the Siberian 

 coast between long. 147° E. and Kara Sea, and of the American coast 

 between Baffin's Bay and Langton Bay, Northwest Territories; 

 Bering Sea and North Pacific Ocean southward on the Asiatic side 

 to Korea and perhaps Amoy, and on the American side to the State 

 of Washington; North Atlantic Ocean southward on the American 

 side to Cape Hatteras, and on the European side to the English 

 Channel. 



KEY TO THE AMERICAN SPECIES AND SUBSPECIES OF THE GENUS HYAS 



A^ Carapace subtriangular; hepatic region not dilated laterally. Basal antennal 

 article subtriangular araneus, p. 253. 



A-. Carapace lyrate; hepatic region dilated laterally forming, with the post- 

 orbital region, an alate expansion. Basal antennal article with sides 

 nearly parallel. 



