212 BE. KNUD ANDERSEN ON BATS. [^P^'- '^' 



m, ; but its postero-external portion cannot, so far as I can see, 

 be touched, by m^. 



m^ (text-figs. 41 b, c). — Longer than broad, abruptly narrowed in 

 front. Cusp 1 practically wanting ; in some specimens of A.plaiii- 

 rostris (and, more often, in A . jmnaicensis) a faint trace of cusp 1 

 is detectable, as an excessively small prominence, immediately in 

 front of cusp 2, but generally it has entirely disappeared and only 

 its commissure with cusp 4 been partly preserved ; it is the constant 

 pressiu'e of this portion of m^ against the anterior margin of the 

 heel of p^ which has caused the disappearance of cusp 1. Cusp 2 

 strongly developed, as a high slender cone, situated very near the 

 middle of the labial margin, close to, but not contiguous with, 

 the cingulum ; this cusp works against the postero-internal portion 

 of the heel of p*, which it has pressed low and concave. Cusp 3, 

 at the postero-internal corner, extremely small, barely projecting 

 above the level of the cingulum, acts against the hinder face of 

 cusp 6 of m^ Cusp 4 (antero-externally) long, but low, tri- 

 angular, trenchant, acting against the heel of p* ; the action of 

 this cusp is the chief cause of the strong development of the heel 

 of p*. Cusp 5 (postero-externally) long, much lower than cusp 4, 

 only slightly projecting, triangular ; it works against the external 

 half of the crushing surface of m^ (the depression bordered by 

 cusps 4-5 and cusp 6 of this tooth). The enamel of the crushing 

 surface of m^ is densely wrinkled. 



m„ (text-figs. 41 b, c). — Slightly smaller than m^, subrectangular, 

 a little longer than broad. Cusp 1 is represented by a very small 

 (but distinct) tubercle at the middle of the front margin of the 

 tooth. Cusp 2, antero-internally, quite of the same shape as the 

 corresponding cusp in m^, only slightly lower ; the action of this 

 cusp is the chief cause of the strong development of cusp 7 in m\ 

 Cusp 3, postero-internally, quite small, but not so strongly reduced 

 as in m^ ; it acts against the postero-external face of cusp 6 and 

 the front of cusp 7 of m^. Between cusps 2 and 3 the cingulum 

 has developed an exceedingly small supplementaiy cusp. Cusps 

 4 and 5 very similar to the corresponding cusps of m^, but much 

 lower ; the former acts against the posterior portion of the 

 crushing surface of m^ (lingually to cusp 5), the latter against the 

 large crushing surface of m^ (between cusps 4 and 5 externally, 

 and cusp 6 internally), which it has made deeply concave. 

 Crushing surface of m^ wrinkled as in m^. 



m.^ (text-figs. 41 b, c). — Rudimentary, -1— jy- the size of m^. 

 Cusps 2 and 4 a,re rather easily detectable. It works against the 

 postero-internal margin of m' and the antero-internal portion of 

 the rudimentary m^. 



Uroderma Pet. 



1865. TTroderma Peters, MB. Akad. Berlin, pp. 587-88, footnote.— Type : Fln/llo- 

 stoma personatnm Vet. 1865 (not Wagner) = TTroderma hilohatum Pet. 1866. 



1878. Artiheus Leach (partim), Dobsoii, Cat. Chir. Brit. Mus. p. 514. 



1901. Uroderma Pet., Relin, Proc. Ac. Nat. Sci. Philad. 1900, p. 757 (9 Febr. 

 1901). — Remarks on the genus. 



