OCT., 1900.] FAUNAL DISTRICTS. 15 



squirrel {^Sperino^Jdlus osgoodi)^ Dawson red-backed mouse {Eootomys 

 dawsoni), yellow-cheeked vole {Microtus xanthognathus), Yukon lem- 

 ming {Lemm.usyuJione7isis)^ Dall varjang hare {Lejms americanus dall'i)^ 

 and tundra weasel {Putorms arcticui). Of the birds, the most char- 

 acteristic are the duck hawk {Falco peregrinus anatum)^ pigeon hawk 

 {Falco coluijiharius)^ Alaska longspur [Calcarius lajpjponicus alascensis)^ 

 hoary redpoll {AcantJds Iwrnemannl exlllpes)^ fox sparrow {Passerella 

 illaca)^ Bohemian waxwing {ArnjJelis gai'mdtis)^ and wheatear {Saxicola 

 mnanthe). 



Alaska Tundra district. — The Yukon from Andraefski to the coast 

 of Norton Sound is bounded on ])oth sides by typical tundra. The 

 country is low and gently undulating, and its surface a short distance 

 away appears to be thickly carpeted with grass. That this is not the 

 real condition a short walk ashore soon demonstrates; but the delusion 

 is so complete that were it not for the presence of the great river one 

 might fancy himself looking out over the undulating plains at the 

 eastern base of the Rocky Mountains in the western United States. 



The flora of the tundra, though devoid of trees deserving of the 

 name, is found on careful examination to ])e quite varied. Besides 

 the numerous mosses and heathers and many small berry-bearing 

 plants are dwarf willows, birches, and alders. The alders attain the 

 greatest size, but are usually found in isolated clumps in favorable 

 spots, where they often grow from 6 to 8 feet high. The ground is 

 frozen a few inches below the surface, and the heavy, spongelike cover- 

 ing of vegetation is kept constantly saturated. Occasional high bluffs 

 on the coast in exposed situations are bleak and bare, but besides 

 these there is scarcely a spot not covered Avith low, matted vegetation. 

 Numerous small ponds are irregularly distributed over the tundra, 

 and around them the vegetation is ranker than elsewhere. Broken 

 lava borders the shores of St. Michael Island, and small moss-covered 

 heaps of it, which form practically the only solid footing on the island, 

 are scattered about over the tundra. 



Characteristic mammals at St. Michael are the Hall Island fox 

 ( Vul^yes hallensis), Nelson vole {Microtus ojMrarius), tundra red-backed 

 mouse {Evotoinys dawsoni alascensis), Nelson pied lenmiing {Dicro- 

 stmiyx nelsoni), Alaska lemming {Leminus alascensis)., and Alaska Arctic 

 hare {Zejms otJuis). Land birds known to breed are the hoary redpoll 

 [AcantMs Iwrnemanni exiUpes)^ common redpoll (Acanthis linaria), 

 Alaska longspur {Calcarius lajjponicus alasccmsis)., western tree spar- 

 row {Sjnzella inonticola ochracea)., golden-crowned sparrow {Zonotrickia 

 coronata)., and Siberian yellow wagtail {Budytes Jlavus lev cost?' iat us). 

 Common tundra plants^ are Cassiopea tetragona., Andromeda x>oli folia., 

 Vaccinium, vitisidcea., Mairania alp>ina.. Ledum palustre, Artemisia 



^Nelson, Report upon Natural History Collections in Alaska, 30, 1887. 



