CHEIROPTERA. 17 



and which does not, in most instances, frequent the same 

 caverns. 



FOSSIL CHEIROPTEROUS (?) INSECTIVORE. 



As we pass to lower and older a Fig. 7. 

 geological formations, our compari- 

 sons lead to different conclusions. 

 Such remains as may with any pro- 

 bability be referred to the Cheiro- Twice nat. size, 

 pterous Order, cannot be satisfactorily identified with known 

 existing species, unquestionably not with any that are in- 

 digenous. In regard to the small molars, already referred to, 

 (p. 12,) which were associated with the Macacus and Hyra- 

 cotherium, in the Eocene sand at Kyson in Suffolk, one of 

 these (a penultimate or antepenultimate grinder,^. 7, a) 

 has the crown composed of four triangular prisms, placed in 

 two transverse rows, with an angle turned outwards, 

 and a side or flat surface inwards, the summits being sharp- 

 pointed. The exterior prisms are the largest ; the crown 

 swells out abruptly above the fangs, defending them, as it 

 were, by an overhanging ridge. There is a small transverse 

 eminence, or talon, at the anterior part of the crown ; and 

 a very small tubercle is placed between the bases of the 

 two external prisms. 



The second molar (fig. 7, 5) differs from the preceding 

 in having the two posterior prisms suppressed, and replaced 

 by a flattened triangular surface. The anterior prisms are 

 present, and their apices project far beyond the level of 

 the posterior surface. There is a small ridge at the anterior 

 part of the tooth. 



These teeth agree very nearly with the antepenul- 

 timate and last molars of the larger insectivorous bats : 



c 



