THE FAMILIES AND GENERA OF BATS. 
177 
dontidse have been almost universally associated with the Phyllo- 
stomidse. Winge placed Brachyphylla with them, but otherwise they 
have been regarded as the only members of the group. 
Remarks. — The Desmodontidse are somewhat closely related to the 
Phyllostomidse, as shown by the structure of the palate, wing, and 
shoulder girdle, but their modification for strictly sanguivorous 
habits is so extreme that it seems quite unnatural to retain them in 
the same family. It is hardly possible to suggest which group of 
the Phyllostomes is likely to contain their nearest allies, though a 
possible relationship with the Hemiderminse is suggested by the 
noticeably trenchant molars of Rhinophylla. 
Principal subdivisions. — The members of this family represent 
three genera. 
KEY TO THE GENERA OF DESMODONTIDiE. 
Outer lower incisor seven-lobed ; lower cheek teeth four Diphylla, p. 179. 
Outer lower incisor with not more than two lobes ; cheek teeth three. 
Inner lower incisor deeply two-lobed ; thumb about one-fifth as long as 
third finger Desmodus, p. 177: 
Inner lower incisor with large median lobe and a minute outer and 
inner lateral lobe ; thumb about one-eighth as long as third 
finger Dicemus, p. 178. 
Genus DESMODUS Wied. 
1824. Desmodus Wied, Abbild. Naturgesch. Brasilien, 5te Lief., pi. and text. 
1834-36. Edostoma d'Orbigny, Voyage dans 1’Amerique Merid., p. vm. 
1878. Desmodus Dobson, Catal. Chiropt. Brit. Mus., p. 546. 
1905. Desmodon Elliot, Check List Mamm. North Amer. Cont. etc., p. 530. 
Type-species. — Desmodus rufus ^Ni^d—PhyTlostoma rotundum 
Geoffroy. 
Geographic distribution. — Warmer parts of America, north to 
southern Mexico. 
Number of forms. — The type species is the only form of Desmodus 
thus far known. 
Characters. — Dental formula (Plates IX and X, fig. 3) : 
-2-.1. 45--. 1-1 1-1 1-1 1-1 
q 2 -. 1. - 2- 45 ^ 2 - 2’ 6 " 1- 1 ->P m 2-2’ m 1 - 1 - ^* 
Upper incisors very large, almost completely filling space between 
canines, the two teeth in contact anteriorly to beyond middle, strongly 
projecting, with acute triangular point and long, very sharp, slightly 
• concave cutting edge. Lower incisors minute, straight, in pairs at 
outer sides of two deep pits in which the upper incisors fit when jaws 
are closed; the pairs separated from canines and from each other by 
spaces about equal to their own length. The crown of each tooth is 
deeply bilobed at the apex, the inner lobe slightly the larger. 
25733— No. 57—07 m 12 
