66 
ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 
Length from nose to root of tail 
of tail 
from nose to ear 
In. Lines. 
6 0 
4 9 
Length of tarsus (claws included) . 
of ear 
In. Lines. 
. 1 2 
. 0 7 
1 3 | 
Habitat, Chatham Island, Galapagos Archipelago, Pacific Ocean, {October.) 
This species is less than Mus Rattus. The upper parts of the body have a 
slightly variegated appearance. 
The skull of Mus Galapagoensis (Plate 33, fig. 8, a,) is rather smaller than 
that of M. Rattus, the nasal portion is proportionately longer, the cranial 
shorter, and the interparietal bone is smaller, especially in antero-posterior 
extent; its length is 15 lines, and its breadth is lines. The lower jaw is 
figured in Plate 34, fig. 14, a. Fig. 8, b, of Plate 33, represents the molars of the 
upper jaw, and fig. 8, c, those of the lower jaw. 
“ This mouse or rat is abundant in Chatham Island, one of the Galapagos 
Archipelago. I could not find it on any other island of the group. It frequents 
the bushes, which sparingly cover the rugged streams of basaltic lava, near the 
coast, where there is no fresh water, and where the land is extremely sterile.” — D. 
31. supra fusco-nigrescens, subtus griseus ; pedibus fuscis ; auribus mediocribus, 
caudd, quoad longitudinem, caput corpusque fere cequante: vellere longissimo, molli. 
Description. — Form stout ; ears moderate ; tail equal to the body in length ; 
tarsi moderate ; fur very long. General tint of the upper part and sides of 
the head and body blackish brown with an admixture of gray ; of the under 
parts grayish white ; feet brown, the hairs grayish at the tip : tail black and 
but sparingly clothed with short bristly hairs : ears rather sparingly clothed 
with hairs, which are for the most part of a brownish gray colour. The ordi- 
nary fur of the back is about § of an inch in length and very soft — of a deep 
gray colour, broadly annulated with brownish yellow near the tip and blackish 
at the tip : the longer hairs which are black, measure upwards of 1^ inches 
in length. The upper incisors are of an orange colour and the lower are 
27. Mus Fuscipes. 
Plate XXV. 
black. 
In. Lines. 
In. Lines. 
Length from nose to root of tail . 
6 
6 
Length of ear 
of tarsus (claws included) 
0 6 ± 
1 I 
of tail 
from nose to ear 
4 3 
1 6 
Habitat, Australia, King George’s Sound, {March.) 
