120 
MURIDS. 
The Tawny Lemming. Myodes helvolus. Lemmus heL 
volus, Rich . Zool. Jour. in. 517. A. Georychus? hel- 
volus, Rich. N . Zool. 128. 
a. Alpine swamps, lat. 56°, North America. — Presented 
by Dr. John Richardson. 
Back’s Lemming. Myodes trimucronatus. Arvicola tri- 
mucronatus, Rich . Parry s Second Voy. Append. 809. 
A. Georhychus trimucronatus, Rich. N. Zool. 130. 
a. Woody spots. Point Lake, N. America, lat. 65° to 69j°. 
—Presented by Dr. John Richardson. 
The Lemming. Myodes Lemmus. Mus Lemmus, Linn. 
Pallas , Glires 9 t. 12. a. Mus Norvegicus, Worm . 
Mus Lemmus var. Norvegica, Pallas. Mus Norve- 
gicus, Worm , Mus t. at p. 325. Penn. Syn. t. 25. f. 2. 
a. Norway.— Presented by H. D. Woodfall, Esq. 
The Hudson’s Bay Lemming. Myodes Hudsonius, E. 
Sabine. Parry's First Voy. Supp. 185. Rich. N. Zool. 
132. Mus Hudsonius, Forster. Schreb. t. 196. Arvicola 
Hudsonia, Rich. Parry ’s Second Voy.App. 308. Hud- 
son’s Rat, Penn . Hare-tailed Mouse, Hearne. 
a. Near the sea, Hudson’s Straits, North America. 
The Owinyak or Greenland Lemming. Lemmus Groen- 
landicus. Mus Groenlandicus, Trail . Scoresby, Greenl . 
416. Arvicola Groenlandica, Rich. Z. J. Parry's 
Second Voy. 304. N. Zool. 134. 
a. Sea Coast, Hudson’s Bay. 
c. Saccomyna. 
The Pouched Jerboa Mouse. Dipodomys Phillipsii, 
Gray , Ann. N. H. 
a. Mexico.- — Presented by John Phillips, Esq. 
The Spiny Pouched Rat. Heteromys anomalus, Gray , 
Spic. Zool. i. 10. Mus anomalus, Thompson , Linn. 
Trans, xi. t. 10. Heter. Thompsonii, Lesson. Dasy- 
notus anomalus, Wagler. 
a. Part of the skin and jaws. Island of Trinidad.— Pre- 
sented by John Vaughan Thompson, Esq., F.L.S. 
