A MONOGRAPH OF THE BATS OF NORTH AMERICA. 45 



these are vertically disposed — the latter lying in advance of the former. 

 The upper nostrilbordor is obliquely disposed to form a fleshy band 

 which widens to form the lateral margin of the naked, erect nose-leaf. 

 These margins tend to unite at the posterior surface of the tip of the 

 mid-rib. Lying between the nostrils is a tubercle; above this is a 

 broadly ov^ate, convex mid-rib. A similiar mid rib is seen on the 

 posterior surface. This "fer de lance" is spoken of in general zoological 

 writings as the erect ])art of the nose-leaf The infra-narial outgrowth 

 is disposed laterally. It also is naked, conforms to the large, crescentic 

 mass of muzzle-glands, and is coarsely sinuate on its Iree margin. It 

 unites with the posterior surface of the supra-narial portion at the i)oint 

 where this leaflet frees itself from the head. Below it unites with the 

 fellow of the opposite side across the muzzle by a row of obscure nodules 

 which may form a ridge. A few hair-bearing warts lie in the space 

 between the muzzle-glands and the eye. The upper lip is bordered 

 throughout with marginal papilhe; the lower lip is free from the man- 

 dible its entire length, and furnished with papilhe at the sides only. 

 Near the mentum the papilhe become coarser, and in front of the incisors 

 form a distinct row which is arranged in the form of a semicircle round 

 a distinct, undivided chin plate. The eye is large and conspicuous. 

 The calcar is short, about the length of tarsus; tail none. 



Variations. — The lobe at the free margin of the basal portion of the 

 nose-leaf may be conspicuous or almost absent; a faintly marked cres- 

 cent of minute warts may lie on either side of the u])per lip, in some 

 si)ecimens the basal part may be without tubercle. The external basal 

 lobe of the tragus may be nearly quadrate. The spines on the outer 

 border of the tragus proper are subject to nuich minor variation. 



Coloration. — The color of the hair of this species is subject to great 

 variation,* a circumstance which probably accounts for the number of 

 species which have been proposed. The material at hand has not been 

 sufficient to satisfactorily determine the ranges of variation, I will 

 rest satisfied in defining some of the more marked characteristic types 

 of coloration. 



The prevalent shades, however, are not very broadly differentiated. 

 Fawn, deep sienna brown, mouse-gray with various shades of ashy 

 white tips to the hairs, being the prevalent hues. The degree to which 

 the hair is unicolored or bicolored is also inconstant. Unfortunately 

 the exact localities from which material has been collected in many in- 

 stances are not known. 



In the specimen No. 11187 N. M., Mirador, Mexico, the fur of the 

 crown was white; the longitudinal streaks usually present in Artibeus 

 were apparently absent, but in reality they formed the lateral bounda- 

 ries of the crown. The occiput and back were of a light-gray brown at 

 tip, while the main portion of the hair much lighter. Over the sacrum 



*Dr. J. A. Allen (Hull. Am. Miis., ISill) cntfis iuto a careful comparison of this 

 species from the West lutlies, Bolivia, and Bogota. 



