1908.] DR. KNUD ANDERSEN ON BATS. 209 



sharp, inner margin (next to incisors) rounded, lingual face almost 

 plane. It is the constant rubbing of the labial face of p^ against 

 the lingual face of the upper canine which has made this latter 

 sharp on its hinder margin and almost plane on its lingual face. 



Lower canines (text-figs. 41 b, d). — Very long ; on the inner 

 margin of the tooth, next to the incisors, the cingulum extends 

 only as high as (or veiy little higher than) the level of the cutting- 

 edges of the incisors, and does not form a secondary cusp (compare 

 Uroderma) ; at the base of the hinder margin the cingulum forms a 

 conspicuous shelf-like projection, caused by the constant working of 

 the tip of the upper canine against this part of the cingulum of 

 the lower canine. 



2)^ (text-figs. 41 A, c). — Cusps 1 and 2 are entirely wanting. Cusp 

 3 is represented by a small (but quite distinct), backwardly project- 

 ing prominence at the postero-external base of the tooth. Cusp 4 

 has disappeared. The principal cusp — large, trenchant, raised to 

 about half the height of the canine, very obliquely triangular, its 

 front margin only about half the length of its hinder margin — is 

 cusp 5. The size and shape of this cusp are correlated to the 

 large, very obliquely triangular interspace between the principal 

 cusp (4) of p^ and p^ ; its front margin is precisely of the same 

 length as the hinder margin of cusp 4 of p^, against which it 

 works, and its hinder margin is of the same length as the fi'ont 

 margin of cusp 4 of p^, against which it works. — The tip of the 

 powerful cusp 4 of the lower p^ working against the lingual 

 cingulum of p^ has caused this latter to develop a rather strong, 

 somewhat concave projection (" heel," representing cusp 6) ; also 

 in the unworn p'' the deep, pit-like depression caused by the 

 tip of cusp 4 of p^ is very noticeable. The anterior margin of the 

 heel of p^ is high, prominent, sharp, acting against the trenchant 

 hinder margin of cusp 4 of pj. 



2^^ (text-figs. 41 A, c). — Longer at base, much higher and broader 

 (transversally) than p'", but in many important details of its struc- 

 ture formed after a similar pattern, though on the whole less 

 reduced in size. Cusps 1 and 2 entirely wanting (as in p°). Cusp 3, 

 rather less reduced than in p^, is represented by a low trenchant 

 margin at the postero-external extremity of p^. Cusp 4 (wanting 

 in p'') is present as a mere rudiment at the anterior extremity of 

 the tooth. The principal cusp — still more powerful than in p'', the 

 highest cusp in the upper postcanine series, trenchant, with the 

 outline of an equilateral ti'iangle — is cusp 5 ; its shape is re- 

 markably like that of cusp 4 of p^, against the hindei- margin of 

 which it works ; the strong antero-external cusp (cusp 4) of m^ 

 acting upon the lingual face of cusp 5 of p^ has made this latter 

 somewhat concave in antero-posterior direction. — The whole an- 

 terior portion of m^ (its cusp 4 and the rudiment of cusp 1 , when 

 this latter has not completely disappeared) acting upon the lingual 

 cingulum of p* has caused this latter to develop a " heel" (cusp 6), 

 broader and a little more complicated than in p^ ; the heel is 

 broader, because it is acted upon by the broad anterior portion of mj^, 



14* 



