[5] The dovekie, or black guillemot (_Uria grylle_), breeds in great numbers in the Orkney islands. I believe ornithologists are mistaken in supposing that this bird becomes white or rather grey during the winter. It is only the young birds that are so; the old ones are seen in winter without any change in the colour of their summer plumage. [6] This place is laid down on the chart as an island, but is a peninsula according to the account we received from the Esquimaux. APPENDIX. LIST OF MAMMALIA, _Collected during Mr. Rae's Expedition, with Observations by J. E. Gray, Esq., F.R.S. &c._ 1. _Mus Musculus._ Linn. York Factory. Probably introduced from Europe. 2. _Arctomys Parryi._ Richardson, Faun. Bor. Amer. p. 158, tab. 10. 3. _Lepus Glacialis._ Leach. Richardson, Faun. Bor. Amer. 221. MYODES.--The specimens brought by the expedition have enabled me to make some corrections in the characters assigned to these species. I may observe that the large size or peculiar form of the claws which has been regarded as a character of the species, appears to be peculiar to one sex--probably the males. 1. _The upper cutting teeth narrow, smooth without any longitudinal groove. Thumb with a compressed curved acute claw._ (Lemnus). _Myodes, Lemnus Pallas._ Glires 77 of Sweden. _Myodes Helvolus._ Richardson, Faun. Bor. Amer. p. 128, belong to this section. All the museum specimens of these species have small, simple, curved, acute claws. 4. _Myodes Hudsonius._ Richardson, Faun. Bor. Amer. 132. Grey, black washed beneath white, sides reddish, sides of the neck red, nose with a central black streak, claws of male(?) very large, compressed, equal, broad to the end, and notched; of female small, acute. In winter with very long black white-tipped hairs. Mr. Rae brought home two males, one in winter and one in change fur, and two females in summer fur. 5. _Myodes Greenlandicus._ Reddish-grey, brown, black varied, back with a longitudinal black streak, beneath grey brown, chest, nape, and sides ruffous. Front claw of males(?) compressed, curved, the under surface (especially of the middle one) with a broad, round, expanded tubercle. I have not seen this species showing any change in its winter fur. 2. _Upper cutting teeth broader, with a central longitudinal groove. The claw of the front thumb strap-shaped, truncated, and notched at the tip._ 6. _Myodes Helvolus._ Richardson, Faun. Bor. Amer. 128. (female?) Fur very long, black, grey-brown; black grizzled, hinder part of the body reddish, beneath grey, sides yellowish. Claws of the fore feet (of the males?) large, thick, rounded, curved, bluntly truncated at the tip; of the female compressed, curved, acute. 7. _Myodes Trimuconatus._ Richardson, Faun. Bor. Amer. 130.