270 BULLETIN 120, UNITED STATES NATIONAL MUSEUM 



Range. — From west Greenland (lat. 70° 25' N., Hansen) and east 

 Greenland (lat. 66° N., Dons) to Hudson Strait and Bay, thence 

 south to Cape Hatteras, North Carolina (lat. 35° 43' N.). 



Langton Bay, Northwest territories, Canada; from Point Barrow, 

 Alaska, to Bering Strait and southward in American waters of Bering 

 Sea to lat. 56° 10' N.; thence southward via Kamtchatka and Sak- 

 halin Island (Japan) to Yezo Strait and through the Sea of Japan to 

 Korea (lat. 37° 02' N., Hansen), ursinus form. Shanghai (see table); 

 Amoy (lat. 24° 30' N., Hansen). 



Iceland; Arctic coast of Europe to long. 49° E. (Birula) and lat. 

 79° 30' N. at Spitzbergen (Dons) ; northern Europe southward to 

 about latitude 49.5° N. (Dons). 



Coast of Siberia and northward, as far west as Bennett Island 

 (about 147° E.) and north as 76° 50' N. (Bu-ula) to East Cape. 



Depth, low-water mark to 373 fathoms, exceptionally 906 fathoms 

 (W. Atlantic) . 



Material examined.— See table, pages 260-268. 



HYAS LYRATUS Dana 



BLUNT-NOSED CRAB 



Plate 235 



Hyas lyratus Dana, Amer. Journ. Sci., ser. 2, vol. 11, 1851, p. 268 (type- 

 locality, ad oras Oregonenses; type not extant); U. S. Expl. Exped., vol. 

 13, Crust., pt. 1, 1852, p. 86; atlas, 1855, pi. 1, fig. la-d. — Rathbun, 

 Proc. U. S. Nat. Mus., vol. 16, 1893, p. 72, pi. 3, and synonymy. — 

 Holmes, Occas. Papers Calif. Acad. Sci., vol. 7, 1900, p. 32, and synonymy. 



Hyas coarctatus Dons, Troms0 Mus. Aarshefter 34, 1912-13, p. 158 (part: 

 lyratus form). 



Diagnosis. — Carapace lyrate; angle of hepatic margin acute or 

 subacute. Basal antennal article with a large, smooth, round tuber- 

 cle at antero-external angle (fig. 90, c). 



Description. — Carapace more lyrate than in H. coarctatus; the 

 lateral expansion of the hepatic region is more pronounced and is 

 produced to a subacute angle. Surface less convex antero-poste- 

 riorly. The lines of tubercles, median, marginal and branchial, are 

 stronger; two large median gastric tubercles, and on either side and 

 a little in advance of the anterior of these, another large tubercle; 

 cardiac region surmounted by a tubercle, a larger one on the intestinal 

 region; a pointed tubercle on the posterior margin of the hepatic 

 expansion. A narrow cleft between the rostral horns, tips more 

 widely separated. Margins of basal article of antenna armed with 

 a few small conical tubercles including one at the extremity of the 

 inner margin; at the extremity of the outer margin a very large, 

 smooth, spherical tubercle, which is partly visible from above and 

 alone serves to distinguish the species not only from others of this 



