. Bulletin - United States National Museum. Science. THE SPIDER CRABS OF AMERICA 269 H. coarctatus alutaceus has an extensive range. According to Birula (1910) it reaches as far north and west as Bennett Island on the Siberian coast, thence eastward to Bering Strait and southward through the width of Bering Sea to Okhotsk Sea and the southern shore of Sakhalin Island. Further south, Sea of Japan to Shanghai, there is another well marked subspecies, Eyas coarctatus ursinus, to be dealt with elsewhere. In the Arctic, alutaceus occurs also east of Bering Strait as far as Point Barrow, Alaska, and
. Bulletin - United States National Museum. Science. THE SPIDER CRABS OF AMERICA 269 H. coarctatus alutaceus has an extensive range. According to Birula (1910) it reaches as far north and west as Bennett Island on the Siberian coast, thence eastward to Bering Strait and southward through the width of Bering Sea to Okhotsk Sea and the southern shore of Sakhalin Island. Further south, Sea of Japan to Shanghai, there is another well marked subspecies, Eyas coarctatus ursinus, to be dealt with elsewhere. In the Arctic, alutaceus occurs also east of Bering Strait as far as Point Barrow, Alaska, and again in Beaufort Sea, Northwest Territories. Although from this point to the Green- land coast the species is absent, it is the same form, alutaceus, which ap- pears in lat. 70° 25' N., West Green- land, and is continued thence south- ward, by way of Hudson Strait and Bay to Labrador, Newfoundland, and Cape Breton. At Newfoundland and farther west and south, that is, from Nova Scotia, by way of Gulf of Maine, to North Carolina, the form changes, but not abruptly, into the typical coarctatus of the British Isles. This form, follow- ing the general direction of the Gulf Stream, is continued northeasterly from the Carolina coast to north- western Europe; thence it extends eastward in the Arctic only to the Murman Sea and therefore fails to connect with the Siberian range of alutaceus by nearly 100° of longitude. Besides the geographical variation there is much individual varia- tion even in specimens from the same gathering, regardless of age or sex. This makes the definite division into separate forms very diffi- cult and unsatisfactory. Some of the variations are noted in the last column of the distribution table. Measurements.—'LdiVgast specimen, male, examined (Grand Banks, alutaceus, 40182), length of carapace 80, greatest width mm. Male (west Greenland), length 99, width 74 mm. (Hansen). Largest American specimen, male, of typical form examined (off Cape Cod, 4555
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