96 ZOOLOGY OF THE VOYAGE OF THE BEAGLE. 



pale. The tail is furnished throughout with minute decumbent hairs, excepting 

 a small naked space at the tip beneath, of about one line in length ; on the 

 upper surface they are brown, and on the under, they are whitish. The 

 fur of the upper and under parts of the body is deep gray at the base ; on 

 the lower part of the cheeks, chin, and on the mesial line of the throat and 

 chest, the hairs are uniform — not gray at the base. The ears are brown, 

 and to the naked eye, appear naked. 





In, Lines. 



Length from nose to root of tail . .46 



of tail 4 4 



of tarsus (claws included) . .0 7^ 



Length from nose to ear 



of ear 

 width of ear 



In. 



Lines. 



1 



H 







' 7i 







n 



Habitat, Valparaiso, Chile, {October.) 



This little Opossum, which is the only species I am acquainted with from the 

 west side of the Cordillera, was exhibited at one of the scientific meetings of the 

 Zoological Society, and its characters were pointed out by Mr. James Reid, who 

 proposed for it the specific name of horlensis* a name which was given from the 

 circumstance that in Mr. Darwin's notes it is stated that a small Opossum was 

 found in a garden at Maldonado. These notes however refer to the Didelphis 

 brachyura. The skull of this animal is figured in Plate 35. Fig. 5, a, re- 

 presents the upper side ; 5, b, the under side ; and 5, c, is the side view. Fig. 5, d, is 

 the lower jaw, and 5, e, is the same magnified. The length of the skull is 14| lines ; 

 width, 8 lines; length of palate, 7| lines; inter-orbital space, 2* lines; length of 

 ramus of lower jaw, 1<H lines. In the palate are two long openings which commence 

 opposite the posterior false molar, and terminate opposite the hinder portion of the 

 penultimate true molar : the incisive foramina are nearly one line in length. On 

 the posterior portion of the palate there are four other foramina, one on each side 

 near the posterior molar, and one on either side the mesial line, behind the large 



palatine openings above mentioned. 



" These little animals frequent the thickets growing on the rocky hills, near 

 Valparaiso. They are exceedingly numerous, and are easily caught in traps 

 baited either with cheese or meat. The tail appeared to be scarcely at all 

 used as a prehensile organ ; they are able to run up trees, with some degree of 

 facility. I could distinguish in their stomachs the larvae of beetles."— D. 



■ 



• See Proceedings of the Zoological Society of London for January, 1837, p. 4.; its characters were not 

 published. 





