1915.] Allen, Review of the South American Sciuride. 230 
Mesosciurus neseus (G. M. Allen). 
Sciurus estuans hoffmanni Roprinson, Proc. U.S. Nat. Mus., XVIII, p. 651 (in 
text), Aug. 12, 1896. Margarita Island, Venezuela. Incidental reference. 
_ Scwurus neseus G. M. AuuEN, Proc. Biol. Soc. Washington, XV, p. 93, April 25, 
1902.— Oscaoop, Field Mus. Nat. Hist., Zodl., X, No. 4, p. 26, Oct. 20, 1910. Mar- 
garita Island. 
Type locality.— El Valle, Margarita Island, Venezuela. 
Geographic distributcon— Known only from Margarita Island, Vene- 
zuela. 
Description.— Pelage long and soft. Upperparts light ochraceous, 
sparingly sprinkled with black; underparts bright orange-rufous; tail exter- 
nally, both above and below, ochraceous, the hairs with a narrow median 
and a broad subapical annulation of black. 
Total length (2 specimens, collector’s measurements), o 380, 9 405; 
head and body, 218, 217; tail vertebree, 162, 188; hind foot, 45, 50; ear, 
18, 18. Skull (same specimens), total length, o’ 50, 9 51; zygomatic 
breadth, 28.3, 29; interorbital breadth, 17, 16.2; breadth of braincase, 
22.5, 22: length of nasals, 15, 15; diastema, 12, 12; maxillary toothrow, 9, 
8.8. 
Specimens examined, 3.— Venezuela: Margarita Island, 3 (Field Mus., 
2, Br. Mus, 1}. 
Remarks.— Mesosciurus neseus is a surprisingly distinct form; in colora- 
tion it is unique among South American Sciuride, having no close resem- 
blance to any of them. In size and proportions it 1s intermediate between 
its two mainland neighbors, M. griseogena and M. chapmani, and may have 
been derived from either, perhaps more probably from the former. It has 
evidently been long isolated from any mainland stock. | 
Mesosciurus griseimembra (Allen). 
Guerlinguetus griseimembra ALLEN, Bull. Amer. Mus. Nat. Hist., XX XIII, p. 
589, Oct. 8, 1914. | | 
Type locality.— Buenavista, eastern slope of Eastern Andes, about 50 
miles southeast of Bogota, Colombia; altitude 4500 feet. 
Geographic distribution.— Eastern slope of the Eastern Andes, from near 
Bogota south to Andalucia. 
Description.— “ Upperparts finely grizzled ochraceous orange and black, 
not appreciably darker on the median dorsal area; underparts washed with 
pale ochraceous buff, strongest over the pectoral region, paler on the lower 
