THE FAMILIES AND GENERA OF BATS. 
115 
Characters. — Dentition essentially as in Hipposideros, except that 
there is only one upper premolar and the upper canine has a large 
secondary cusp rising to middle of posterior side of shaft. General 
form of skull as in Hipposideros. Rostrum moderately swollen 
and distinctly lower than braincase. Premaxillaries unusually thick, 
forming along line of contact a distinct ridge which terminates 
anteriorly in a noticeable backward-curved point. Zygoma greatly 
expanded posteriorly, the expansion conspicuously narrowed above, 
its height fully equal to distance between last molar and glenoid fossa. 
Sagittal crest beginning at middle of posterior portion of braincase 
(the hindermost rounded part of which is smooth) its height increas- 
ing rather rapidly until slightly in front of middle of braincase it 
reaches 1 mm. Here it abrupty ter- 
minates in a forward-curved point. 
In front of the crest the median re- 
gion shows the usual ridges, but 
these are so reduced as to be 
scarcely visible by the unaided eye. 
Tail well developed, longer than 
femur. 
Species examined. — Rhinonycte- 
ris aurantius (Gray). 
Remarks. — This genus is very 
strikingly characterized by the 
large secondary cusp of the upper 
canine and the peculiar cranial 
characters. 
Genus TRIAENOPS Dobson. 
1871. Triamops Dobson, Journ, Asiat. 
Soc. Bengal, XI, p. 455. 
1878. Tricenops Dobson, Catal. 
Chiropt. Brit. Mus., p. 123. 
T ype-species. — T ricenops persicus 
Dobson. 
Geographic distribution. — Madagascar, eastern Africa, and Persia. 
Number of forms. — Four species of Tricenops are known. 
Characters. — Dental formula and general structure of teeth as in 
Hipposideros , but upper incisors noticeably bifid and upper canine 
with a secondary cusp extending nearly to middle of shaft. Skull 
(fig. 22) with rostral portion greatly developed, much more than 
half as long and nearly as deep as brain case, the anterior nares very 
broad and with a short, but distinct, median spine on posterior border. 
Zygoma greatly expanded throughout, but most conspicuously behind, 
where the height is equal to distance between last molar and glenoid 
Fig. 22. — Tricenops persicus. Aden, Arabia. 
No. 123439. X2. 
