288 U. Ss. P. R. R. EXP. AND SQRVEYS—ZOOLOGY— GENERAL REPORT. 
Measurements of skulls. 
Current Locality. Length. Width. 
number. 
Mi2) Carlisle Pa. cosasa-asaaccooe= g by la ee 
jie Mia Un Se ome le 1.30. | 388 
949 Racine<25--a0-=2- ene 1. 33 . 76 
List of specimens. 
M 
2 Measurements. 
= s 
eal ee 
g | BE Locality. When Whence obtained. | Nature of | From tipofnoseto— | Tailtoend| Length of— 
a rie collected. specimen. oe 
& | a° ao 
S ra 
2 | 5 Eye. | Ear. |Occip | Tail. | Vert. |Hairs.|Fore ft. | Hind ft. 
o 12) 
536 |.eeeee Montreal, Cant:.csccsecccs|ccccctevieccece| LHOMAS BrOOMC.se coe) SKIN is coee |ecuccs}ucess Joccvice| 0.00 |eoe vevece|ceevecce| keaD 
2508 |.....-| Middleboro’, Mass........| Spring, 1856..| J. W. P. Jenks.......| Inaleohol..| .60 | 1,18 | 1.50 | 4.70 | 3.40 | 4,90 87 1.20 
OUD! | Seuwvn|leccsnsGO ss’ scwuen'eWelocss|caectes dO’ oc... Jee sae cpossinessesins wee-GO0.....| .60 | 1.18 | 1.50 | 4.70 | 3.70 | 4.40 80 1.14 
2510 |...0e.| Essex county, N. Y .osecclecceccccsevces| Dr. S. E. Hale .o..00. eieeO) Secce 50 | 1.60 | 1.35 | 3.40 | 2.60 | 3.00 70 1,09 
860 |...... New York city..... scvwaklivede ee eseseese| Geo. N. Lawrence ...| SKin .. ....|ecess casanafenunsi 5.00 | 2.90 | 4.10 |.....06. 1.14 
cocceelcovces| Washington, D. C..cces..|ccseceeevceces| Dis Nichols ..00cccees In alcohol..|....--|+++ wec|occcer|sccces veceee|ceccee|sacsccce|cccscece 
2504 |.....-| Columbus, Ga..... Sasecs|escees ccccceee| Dre W. Gesner coceee|oresO socee 60 | 1.20 | 1.50 | 4.76 | 3.60 | 4,20 73 119 
Q5US |ecccealescces dO .ccceee seccccvecelececs eo teeccees On vey 55 | 1.14 | 1.46 | 4.55 | 3.50 | 4.18 -70 1,10 
2506 |..e0ce West Northfield, Il a |saeeO festa = 60 | 1.20 | 1.50 | 4.76 | 3.60 | 4.30 73 1.23 
827 |......| Racine, Wis.......000 SKM sraae s/spanie'|wadelein' iden cma] pb) 00),| arreeapl mbna enveinece) (LCR0 
BBN ieence| ceases dO .see0 susneccelecnscecessuces pee sOO's coneil eeamaisl|anenc seeee | 4.20 | 3.40 | 4.10 |....0006] 1.05 
780" | Saves of (COLUMDUH, MISS J, . spe tecn|sacscsecccsces In alcohol... |....0.|sesees|eeeee| 39-00 | 3,60 | 4.10 |......05) 1.10 
187 \ecccca|vecens dO. .cccves cecccccce|cccreccscesece 2000 a cees |ecccrsievcces|eecees 4.80 | 3.40 | 3.90 |...ee0ee| 1.02 
1259 | 342 | Prairie Mer Rouge, La....|...seeeseeeees Mounted... |..++++ cocvcelevcecs| cocree|evesce|scceceleoee cocsleccvesce 
QBSB jeccces|eccecedO . coscccce.ccaseve|vocceveccuccce o| SKin.. ccc] eewece secceelece oe] 5.20 | 3.20 | 4.00 |....0000| 1.08 
PTEROMYS HUDSONIUS. 
Northern Flying Squirrel. 
Sciurus hudsonius, Guextn, Syst. Nat. I, 1788, 153. 
Pteromys hudsonius, Fiscuer, Synopsis, 1825, 365. 
Sciurus sabrinus, SHAw, Gen. Zool. Mamm. I, 1801, 157. 
Pteromys sabrinus, Ricu. Zool. Jour. IIT, April, 1828, 519.—Is. Fauna Bor. Amer. I, 1829, 193. 
Waener, Suppl. Schreber, II, 1843, 228. 
Aup & Bacu. N. Am. Quad. III, 1853, 202; plate cxliii, fig. 1. 
Severn river flying squirrel, Pennant, Hist. Quad. II, 1781, 418.—In. Arctic Zool. I, 1784, 122. 
Sp. Cu.—Considerably larger than the P. volucella, or common flying squirrel. Tail considerably shorter than the head 
and bedy; (shorter than the body alone?) Above, yellowish brown; beneath, white; the hair plumbeous at root. 
Length of head and body about eight inches; of tail, with hairs, 53. Hind foot, 1. 60 inches. 
I regret that the only materials at my command for the description of this species consist of 
some very imperfect skins. In these the only differences from Pteromys volucella I can realize 
are the considerably larger size, and the under hairs of the belly, instead of being white at the 
roots, are lead colored. ‘The tail is proportionally shorter. In almost every respect, however, 
the one is a miniature of the other. The upper part of the tail is colored like the back, some- 
times with a mixture of darker towards the tip. 
