184 



NORTH AMERICAN FAUNA. 



[NO. 27. 



after the snow had melted, came from that place, where he spent the 

 spring of 1826. (See footnote.) 



Arvicola Ijorealis has been variously referred by authors to 

 Arvicola^ Microtus^ and Phenacomys^ usually to one of the two first- 

 mentioned genera. A careful study of the very full description in 

 Fauna Boreali- Americana, however, seemed to point so strongly 

 to Synaptomys that I felt reasonably sure that it actually referred 

 to that genus. On visiting Fort Franklin in September, 1903, there- 

 fore, I made a special effort to ascertain if Synaptomys inhabited 

 the region and was rewarded by the capture of 8 specimens, includ- 

 ing adults of both sexes and nearly grown young. These specimens 

 accord so well with the later detailed description that there is no 

 doubt of the advisability of applying the name horealis to this ani- 

 mal. It may be well to quote the more pertinent portions of Rich- 

 ardson's description : 



The body and head are clothed with fur, which is very long in proportion to 

 the size of the animal. The fur on the upper parts is shining blackish-gray, 

 from the roots to the tips, some of which are yellowish or chestnut-brown, 

 some black. The hairs with black tips are the longest, and are equally dis- 

 tributed amongst the others, giving the whole a dark umber or liver-brown 

 color, but producing no spots. There is a rufous mark under the ears. The 

 fur on the back is about ten lines long, that on the crown of the head is three 

 or four. The fur on the under parts (including the chin and lips) has a lead- 

 gray colour, and is shorter than that covering the back and sides. The tail is 

 round, well clothed with short, stiff hairs, which do not permit any scales to 

 be seen. It is clove-brown above, and grayish-white beneath. * * * The 

 thumb of the fore-feet consists merely of a small strap-shaped nail, slightly 

 convex on both sides, and having an obtuse point projecting from the middle 

 of its extremity. (Fauna Boreali Americana, I, p. 127, 1829.) 



Among the dimensions given the length of tail (1 inch=26 mm. 

 approximately), and the length of hind foot (7^ lines=17 mm. ap- 

 proximately), accord well with the measurements of Synaptomys.^ 



The first specimen of Synaptomys taken during the summer of 

 1901 was trapped on June 12 in a Microtus runway, on the border of 

 a small meadow near Slave River, 25 miles below the mouth of the 

 Peace. A few days later we took two in a wet swamp near Smith 

 Landing. We did not detect the species at Fort Smith nor at Fort 

 Resolution. On July 17 I took two specimens at Trout Rock, 25 

 miles south of Fort Rae, and during the latter part of the month 

 trapped a few about small muskeg ponds at Fort Rae. One taken 



^ Since the above account was written all question as to the application of 

 the name horealis to this species has been removed by an examination of the 

 type in the British Museum by W. H. Osgood, of the Biological Survey, who 

 has found it to belong to the genus Synaptomys. Its label bore the following 

 legend: ''Arvicola horealis. Mouse A. 42. 10. 7. 10. See p. 12. Note book, 

 Awinnak, Dog-ribs, 4^ inches long exclus. tail. Fort Franklin. Dr. R." 

 (Proc. Biol. Soc. Washington, XX, p. 49, 1907.) 



