286 



DR. KNU.D ANDERSEN ON BATS. 



[Apr. 7, 



ledge, whereas in jamaicensis (and in concolor, jjlanirostris, and 

 hirsutus) it is equal to fi-om one-third to one-fifth the area of the 

 tooth. The angular emargination in the posterior border of m" 

 (into which m'' is pressed in those species which possess this 

 rudimentary tooth, and which, as pointed out above, pp. 250-252, 

 is very often preserved in A. jamaicensis, although this species 

 has lost m'') is in glauciis but faintly indicated, the whole postero- 

 internal portion of ni" being foi-med by the slightly projecting 

 cusp 7. — The lower teeth do not diflfer in structure from those of 

 the foregoing species ; the small m., is still more reduced in size. 



Text-fig. 53. 



A. Art iheus glaums, $ ad. Chanchamaj'o, Peru. Type, B.M. 94.8.6.13. 

 Eight upper tooth-row. X j- 



B. Artiheus jamaicensis jamaicensis, $ j'g. ad. Jamaica. B.M. 7.1.1.677. 

 Right upper tooth-row. X f- 



Nose-leaves. — Front margin of horseshoe free, simple. 



Tragus. — Two indistinct serrations on the outer margin above 

 the median projection ; in a larger series some individual variation 

 will be found in this respect. 



Wings. — The third, fourth, and fifth digits are proportionately 

 longer than in the planirostris and ja^naicensis sections ; in 

 planirostris the indices of these digits (including the meta- 

 carpals, but excluding the terminal cartilaginous rods of the 

 distal phalanges) are, respectively, 1945, 1477, and 1346; in 

 glaucus and ivatsoni (which are similar in the wing-structure 

 as in almost all other respects), 2025, 1497, and 1405 ; as 

 proved by these figures, particularly the third and fifth 

 digits are lengthened*, to a less degree the fourth. A 



* " Lengthened " means here simplj' longer as compared with the digits of bats of 

 the planirostris and jamaicensis type ; it does not imply that the writer is of 

 opinion that the wing-structure of glaucus and tvatsoni can, phylogenetically, be 

 derived from that of the planirostris-jamaieensis type. We have no means to 

 determine, with any degree of probability, which of these wing-structures is the 

 more primitive, i. e. comes nearest to that of the prototype of the genus. 



