Mr. 0. Thomas on a neio 3Jexican Bat. ^11 
coast at a place called Miri, North-eastern Sarawak, some 
sixteen miles south of the mouth of the Baram River. 
No species appears to have ever been described at all 
resembling this remarkable animal. Its nearest ally is 
perhaps that figured by Peters * under the name of 
>S'. chry sog aster \ but even this relationship is very doubtful, 
the different distribution of the colours and the conspicuous 
difference in the colour of the crown widely separating the 
two forms. 
LX. — Description of a new Mexican Bat. 
By Oldfield Thomas. 
The British Museum has received from Dr. A. C. BuUer 
two bats belonging to the group called Rhogeessa by Dr. H. 
Allen, but clearly differing from Rh. parvula, the only species 
of the group recognized by Dr. Dobson, by whom also the 
group itself was placed simply as a subgenus of Vesperugo. 
This reference I am not disposed to endorse, and think that 
it should rather be looked upon as related to Nycticejus^ with 
which it agrees in the number of its incisors and premolars, 
and from which it differs mainly by the cylindrical form of 
its outer lower incisors. Pending, however, a renewed 
revision of the whole group I propose to use the term Rho- 
geessa in a generic sense. The new species, which appears to 
be of a somewhat annectant nature, I propose to dedicate to 
Dr. Harrison Allen, the chief authority on North-American 
bats and the founder of the group to which I refer it. 
Rhogeessa Alleni, sj). n. 
Decidedly larger than Rh. parvula ; muzzle obliquely 
truncate as in that species. Ears large, laid forward they 
reach about 1 or 2 millim. beyond the nostrils ; their inner 
margin very convex forwards below, straight or even sliglitly 
concave above; tip narrowly rounded off; outer margin con- 
cave below the tip, then straiglit, becoming slightly convex 
below, outer basal lobe but little marked. Tragus long, its 
broadest ))oint opposite to base of its inner edge ; inner edge 
straight or slightly concave^ tip rounded, outer margin slightly 
convex, the edge indistinctly crenulate, somewhat as in 
Antrozous pallidas -^ ; a marked lobule at the base of the 
outer margin, above and below which there is a concavity. 
Thumb very short and thick, no longer than in Rh. parvula, 
* MB. Ak. Berl. 1870, pi. iv. a. 
t There is also a slight crenulatioii in Rhogeessa parvula. 
478 Bibliographical Notices. 
Posterior edges of wing-membrane bordered with white ; bifid 
tip to fourth finger unusually distinct * ; wings from the base 
of the fifth toe ; post-calcareal lobe small and narrow ; tip of 
calcar ])rojecting slightly from the back of the membrane ; 
tail included in membrane to the extreme tip. 
Teeth. — Upper incisors one on each side, long, slender, 
unicuspid ; upper premolars large, quite close to the canines ; 
no trace of a minute anterior premolar. Lower incisors six, 
the four median ones broad, tricuspid ; the outer ones uni- 
cuspid, exceedingly minute, practically invisible from in 
front, and scarcely one twentieth of the size in cross section 
of the median incisors ; far smaller therefore both absolutely 
and relatively than in Rh. parvula. 
Dimensions of the type (an adult female in spirit) : — 
Head and body 47 millim. ; tail 41 ; ear, above head 12'2, 
from notch 16; tragus, inner margin 7; forearm 35; 
thumb 5 ; metacarpal of third finger 33*5 ; lower leg 15*5 ; 
hind foot 7*1 ; calcar 15. 
Skull of a second specimen : occiput to gnathion 14*7 ; 
greatest breadth 9*5 ; distance from front of canine to back of 
Hah. Santa Rosalia, near Autlan, Jalisco, Mexico. 
This interesting species shows a relationship to Nycticejus 
humeralis f and to Old-World Nycticeji by its dental formula 
and the unicuspidate character of its upper incisors ; to Rho' 
geessa by its obliquely truncated muzzle and its cylindrical ,73 ; 
and finally to Antrozous by its crenulate tragus and by the 
extreme reduction of the same o? which is altogether absent 
in that genus. 
BIBLIOGRAPHICAL NOTICES. 
Fur-hearing Animals in Nature and in Commerce. By Henrt 
Poland. Guruey and Jackson. 
Wio are told in the preface that this " work is intended, firstly, to 
aid persons engaged in trade to recognize readily and to have a 
closer knowledge of the animals with which they are to some extent 
already familiar, and which they would have some difficult)- in 
finding in more elaborate and scientific works ; " and in this respect 
* This peculiar bifid tip to tlie fourth digit does not seem to liave been 
often noticed, as I can find no reference to it, although it occurs more or 
less developed in Rhogeessa, Antrozous, Ni/cticejus, Atalapha, and cer- 
tainly in some of the many species of Vesperuffo. 
+ For nomenclature see Ann. Mus. Genov. (2) ix, p. 88, 1890 j and 
Ann. & Mag. Nat. Hist. (0) vii. p. 528 (footnote), 1891.