400 



MR. H. SATJNDEES ON THE GEO&BAPHICAL 



arctic region; and in its immature plumage, and in the pattern of its 

 primaries when adult, seems to have no very close allies. In the 

 Red Sea are found two species, the more specialized of which, 

 L. leucopJithalmus, is restricted to those waters, whilst L. hem- 

 prichii extends its range as far as Scind; like L. atricilla of Ame- 

 rica, they have black primaries, but there are no other points which 

 indicate any special ajOBnity. To sum up the evidence afforded 

 by the distribution of the Hooded Grulls,it cannot be said to amount 

 to much more than a general indication of an origin in eifcher the 

 Palaearctic or Nearctic region, probably the latter, as it is from 

 thence that they have been diffused fas ar as the extreme southern 

 limits of the American continent. 



The genus Pagophila calls for little remark : it contains but 

 one species, the Ivory Gull, P. ehurnea, and is a well-marked, 

 coarse, and purely Arctic form, ranging from Novaya Zemlya to 

 Spitzbergen and Baffin's Bay, but not being as yet recorded 

 from any part of the x^orth Pacific. Another purely Arctic 

 form, tlie small Wedge-tailed or Eoss's Gull, Rhodostethia 

 rosea t Macgill., of which only thirteen specimens are known 

 to exist, has a still more circumscribed range, and its head- 

 quarters appear to be Melville Peninsula, Boothia Felix, and 

 perhaps the region between Spitzbergen and Franz-Joseph land. 

 This beautiful species when in breeding-plumage has a black 

 collar but no hood, the underparts being tinted with a rich rose- 

 colour, whilst the centre feathers of the tail are somewhat pro- 

 longed as in the Skuas, from which group, however, it is in all 

 other respects far removed. This also is an Arctic species with 

 no near allies. The last of the Arctic species is Xema sabinii, 

 a gull but slightly larger in size, with a black hood deepening 

 into a collar, and & forked tail. This gull breeds right round the 

 Arctic circle from Greenland to the Siberian tundras north of 

 lat. 74°, and has been known to push its southern migrations as 

 far as the north of Peru. There is considerable interest attaching 

 to this wanderer in the tropical Pacific ; for at Chatham Island, 

 one of the Galapagos group, and situated nearly on the Equator, 

 was obtained one of the two existing specimens of that rarest of 

 all gulls, X.furcata (Neb.) — a fork-tailed hooded species, which, 

 but for a few trifling details, is a gigantic X. sahinii. Over the 

 real habitat of X. furcata there hangs a slight mystery. There 

 can be no doubt the specimen in the British Museum was ob- 

 tained in the Galapagos group, the very rock (Dalrymple rock. 



