THE FAMILIES AND GENERA OF BATS. 
99 
Remarks. — Except from the next genus Noctilio is so readily dis- 
tinguishable that it requires no special comparison with any known 
group of bats. Externally it is perhaps most easily recognized by 
the excessively long legs and large feet, heavy, bony calcar, and long 
terminal phalanx of third finger, flexed under metacarpal; but its 
strongly wrinkled lips, sharp muzzle, and pointed, erect ears are 
also highly characteristic. In most of its peculiarities, undoubtedly 
to a considerable degree correlated with its largely fish-eating habits, 
Noctilio is the more specialized of the two genera comprised in the 
family. 
1878. Noctilio Dobson, Catal. Chiropt. Brit. Mus., p. 293 (part). 
1904. Dirias Miller, Proc. Biol. Soc. Washington, XIX, p. 84, June 4, 1906 
(albiventer ) . 
Type- species. — Noctilio albiventer Spix. 
Geographic distribution. — Warmer parts of South America. 
Number of forms. — Dirias albiventer (Spix) and D. zaparo (Ca- 
brera). 
Characters. — Like Noctilio externally but with less elongated leg 
and foot, the length of tibia and foot together scarcely exceeding 
40 per cent of the “ total length.” Skull as in Noctilio. Teeth as in 
Noctilio except that the first and second upper molars are very 
slightly emarginate posteriorly, so that the spaces between the teeth 
are scarcely noticeable; liypocone relatively largely than in Noctilio 
and connected by a high, conspicuous commissure, with the commis- 
sure extending from protocone to metacone. 
Species examined. — Dirias albiventer (Spix). 
1821. Vespertilionidce (part; Race 1, part) Gray, London Medical Reposi- 
tory, XV, p. 299, April 1, 1821. 
1827. Rliinolophina Lesson, Man. de Mammalogie, p. 81 (part). 
1831. Vespertiliones ( Vespertilionidpe ) (part; Phyllostomina, part) Bona- 
parte, Saggio di una clistrib. metodica degli Anim. Vert., p. 15. 
1838. Vespertilionidce (part; Rliinolophina, part) Bonaparte, Nuovi Annali 
delle Scienze Natural!, Bologna, Anno I, Tomo II, p. 112. 
1838. Vespertilionidce (part; Vespertilionina, part) Gray, Mag. Zool. and 
Bot., II, p. 494, December, 1838. 
1854. [ Rhinolophicla: ] “ Rliinolophides ” Gervais, Llist. Nat. des Mammi- 
feres, p. 200 (part). 
1855. Nycterina Van der Hoeven, Hanclb. der Dierkunde, 2d ed., II, p. 1028 
(part). 
1865. Megadermata Peters, Monatsber. k. preuss. Akad. Wissensch., Berlin, 
p. 256 (part). 
1866. Rhinolophidce (part; Nycterina) Gray, Proc. Zool. Soc. London, p. 83. 
1872. Megadermidce Gill, Arrangement of the Families of Mammals, p. 17 
(part). 
Genus DIRIAS Miller. 
WfcOC. BIOL. SOC. WASHINGTON, 
