The Bats of British Guiana. 107 
odour arises. In size it is much about the same as the 
preceding species, the wing expansion being, however, 
greater, and reaching to from 14-16 inches. The pecu- 
liar overlapping and infolding of the lips, more especially 
the upper lip, gives a strange aspecl to the face, in- 
creased by the warty and erect small processes on the 
chin. The special character of its teeth, also, well marks 
the form, the median incisors being almost rodent-like, 
though small, and the lateral incisors quite minute and 
almost hidden. 
The RhynchonyClcris naso is the small bat so com- 
monly distributed throughout the colony, and to be found 
in groups resting in the day time on the stumps and 
trunks of trees, especially where they overhang the water, 
along the banks of the rivers and creeks. This is the 
smallest of our bats, and has a spread of wings of about 
S-9 inches. It is of a brownish black and grey colour, 
very closely resembling the tint of the trunks on which 
it settles, and on which, when at rest, it is hardly to be 
distinguished from the knobs and wrinkles of the bark. 
When disturbed, these bats flit along with a quick and 
jerky flight, settling on other stumps in the vicinity. 
They are preyed upon by the common "chicken hawk," 
the Great-billed Buzzard (Asturina magnirostris) , so 
constantly met with in the same localities, and no doubt 
by others also; and the reason of their protective colour- 
ing and form, in adaptation to their surroundings, is thus 
clearly apparent. The muzzle of this species is curiously 
elongated ; the teeth are remarkedly small and fine ; 
and the tail perforates the interfemoral membrane, appear- 
ing on its upper surface. 
Of the three Vespertilionid bats, the two species of 
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