294 DR. KNUD ANDERSEN ON BATS. [^P^. 7, 



Art'ihe2is, chiefly in the strong reduction in the size of nr. m^ not 

 essentially different from that of A. tvatsoni ; cusp 7, if anything, 

 still less developed, represented only by a narrow, slightly pro- 

 jecting shelf, therefore as narrow as in any Ya7npyro2)s, its basal 

 outline almost perfectly quadrate, m^ little more than ^ (in all 

 other species of the genus | or |) the area of m\ but all the 

 elements of the tooth (cusps 4, 5, 6, 7) are distinct, and all of 

 them have been very nearly equally reduced in size, though 

 perhaps cusp 7 a little more than the others. 



Text-fie-. 55. 



Artibeiis rosenlergi, ^ ad. Cacliavi, N. Ecuador. Type, B.M. 97.11.7.76. 



Eight upper (A), left lower tooth-row (B). X f- 



On ms in this species see text below. 



The lower m^ is proportionally a little smaller than usual in 

 the genus, but by no means reduced to the same degree as m" ; 

 the area of m„ is about | (in other species about |-) that of m^. 

 In the type specimen of A. rosenbergi an excessively small m^ is 

 present on the left side, entirely wanting on the light side ; 

 the normal condition is no doubt that m, is wanting. In the 

 material sent for identification from the U.S. National Museum. 

 I find a second specimen of A. rosenbergi (no. 62635 j, in which 

 there is no trace of nig ; and in A. toUecus, which has | molars, 

 one skull, out of 27, has an mg on one side of the mandible, thus 

 showing an individual anomaly apparently perfectly like that 

 of the type skull of A. rosenbergi. 



Tragus and horseshoe. — The tragus has one or two serrations 

 on the outer margin above the median projection. The horse- 

 shoe is free all round, the margin simple or finely crenulate. 



Wings. — The most noteworthy peculiarity in the wing-structure 

 is a conspicuous lengthening of the metacarpals ; the phalanges 

 are very nearly of the same relative length as in ^. glauctis and 

 tvatsoni, the first phalanx of the third digit perhaps not quite as 

 long as in those species. See the wing-indices, p. 310. 



Hairing on limbs and membranes. — Essentially as in the nearest 

 relatives, A. glaucus, watso')ii,~Hnd cinereus. Above, the proximal 

 half of the forearm densely haired ; a tuft of short hairs on 

 first metacarpal ; femur, tibia, foot to the claws, and interfemoral 



