312 
NATURAL HISTORY. 
over the terminal portion of the shank. 
HEAD OF STRAW-COLOUllED RAT. 
(From the Proceedings of the Zoological Society.) 
The thumbs are free ; the legs and tail are long and slender ; 
the latter, which consists of only seven joints, is longer 
than the head and body of the animal, and is almost en- 
tirely enclosed in the ample interfemoral membrane, the 
posterior margins of which are supported by long spurs 
springing from the heels. All the membranous parts, 
including the ears, are thickly marked with dotted lines. 
There are four incisor teeth in the upper jaw, placed in 
pairs, and separated by a space from the canines. There 
are three pre-molars in both jaws. (Dental formula — 
incisors, 2 ~, canines, pre-molars, f - ?, molars, ) 
The Straw-coloured Bat measures about four inches 
in total length, fully one-lialf of which is occupied by 
the tail. It is clothed with a moderately-long fur, of a 
brownish-yellow colour, paler on the lower surface. The 
membranes are reddish-brown. It is an inhabitant of 
South and Central America. 
CHAPTER Y. 
EMBALLOX U R I N E ALLIANCE. 
FAMILY V, — EMB ALLO NURID2B, Oh THICK-LEGGED BATS. 
Characteristics of the Emballonuridce , or Thick-legged Bats— Cuvter’s Fury -The Genus Sacc-optmjx— Striped Sack- 
winged Bat — The Pouch or Sac in the Wing-membrane — Dentition — Mountain Bat — Tomb Bat — Origin of its Name 
—Dentition— The peculiar Sac or Pouch under the Chin Other Species of the Genus (note)— Egyptian Rhino- 
pome — Difficulty of assigning its true place in the System — Characteristics— Great Hare-lipped Bat — Seba’s De- 
scription — Linnieus’s Mistake— Dentition Distribution— The Genus Nyctinomu ft — Cestoni ’s Bat -Pale Chestnut 
Mastiff Bat— Distribution— Habits -Smoky Mastiff Bat— Habits— Collared Bat— Hidaous Ugliness— Charac- 
teristics— New Zealand Short-tailed Bat— Characteristics— Mr. Dobson on the Wing -membrane, Thumb, and 
Foot. 
This family is the first of the second great group into which Mr. Dobson divides the ordinary 
Bats, and it includes many forms which arc almost as typically Bats as the Vetyertihoiiidce themselves. 
As in the Vesper tiliomdce the nostrils are simple, that is to say, they are quite destitute of foliaceous 
appendages, except in one curious genus ( Rhmopoma ), which has a very small nose-leaf. The cha- 
racter of the folding of the first phalanx of the middle finger in repose upon the upper surface of the 
metacarpal bone has already been mentioned as distinguishing the members of this alliance generally. 
It is subject to two exceptions in the present family, being extended in a line with the metacarpal 
bone, in the same way as in the Vespertilionine Bats, in the curious genus NoctlUo , and folded beneath 
the metacarpal in the equally singular genus M tjAachia. In the latter genus, moreover, the middle 
finger has three phalanges, the number of these bones in all other Emba Horn irid ce being two. The 
legs are short and stout, and have the two bones of the shank (tibia and fibula) nearly equally de- 
veloped ; the tail has its basal portion enclosed within the interfemoral membrane, but perforates this, 
on the upper surface, at or beyond the middle, and is usually continued as a free organ for a considerable 
distance beyond this point ; and the upper incisor teeth are generally two in number. 
The members of this family, which are insectivorous in their habits, are chiefly confined to the 
tropical and sub-tropical regions of both hemispheres. A single species inhabits Europe, and one is 
found in New Zealand. 
