From the Proceedings of the Boston Society of Natural History, Vol. XXVI. Read 
Feb. 21, 1894. Author's edition, June 23, 1894. 
ON A NEW SPECIES OF AMETRIDA. 
BY HARRISON ALLEN. 
Ametrida minor sp. nov. Coloration almost white. The third phalanx 
of the third Anger is nearly twice the length of the second. The third 
phalanx of the fourth Anger is a third longer than the second. Much 
smaller, as a whole, than A. centurio. The horizontal plate of the palatal 
bone is not deAcient behind, but extends slightly back of a line which 
Fig. 1. Ametrida minor H. Allen. 
unites the last molars. The posterior nares are remarkably small, being 
contracted to mere pinhead diameters. The superior incisors do not fill 
in the space between the canines. 1894-] 
241 
[Allen. 
Locality unknown. Type, a male, mature individual in alcohol. 
Fig. 1. Museum of the Boston society of natural history. 
Ametrida (A. centurio) was founded by J. E. Gray (Ann. and 
mag. nat. hist., ser. 1, v. 19, p. 407, 1847), apparently on a 
single alcoholic specimen from Brazil. The account is short and 
unsatisfactory. W. Peters (Monatsber. akad. wiss. Berlin, 
1866, p. 396) more fully redescribed the genus from a single dried 
skin (without locality) in the Leyden museum. G. E. Dobson1 
(Cat. Chir. Brit, mus., 1878) gives an extended account of Ame- 
trida, but refers to a single individual from Brazil probably the 
type specimen. Peters, contrasting Ametrida with Sphaeronyc- 
teris (Monatsber. akad. wiss. Berlin, 1882, p. 987) employs char- 
acters not used in his first description ; one can only assume that 
additional material had passed under his observation.2 
Thus the bibliography of the genus is scant. In the long 
period intervening between 1847 and 1893 but two individuals are 
mentioned by authors.8 
The general aspect is that of a species of Stenoderma, but the 
second metacarpal bone is abruptly bent with a convexity outward. 
All the measurements tend to be larger than A. centurio. The 
third phalanx of the third digit is little more than half the length 
of the second. The second phalanx of the fourth digit is longer 
than the first. 
1 Dobson states that the palatal bone in Ametrida centurio is deficient behind, and 
since he is in doubt as to the propriety of separating Ametrida from Stenoderma, it is 
probable that this deficiency is similar to that in Stenoderma and amounts to a deep 
sinuosity of the posterior palatal border. In the Leyden specimen, the parts were said to 
be mutilated; yet Peters in his second paper states that the border is scarcely cut out. 
2 Sphaeronycteris resembles Ametrida in the general shape of the skull, in the 
number of teeth, in the rounded head, in the general shape of the ears and tongue, the 
manner of attachment of the wing membrane to base of toes, in the short calcar, in the 
deeply incised interfem, and in the skin-formations about the nose-leaf. But the nose- 
leaf of itself and the physiognomy are quite distinct. The anterior temporal crest is 
extraordinarily widened; the nose-leaf is surrounded above, and the plicae of the face 
suggest a disposition of parts as in A. centurio. The tragus is more sinuate on the outer 
border. The incisive foramen is very small; the posterior border of the palate reaches 
the level of the second molar; the breadth of the basicranium between the cochleae is 
as wide as the exposed portion of the cochleae themselves. The coronoid process of 
the lower jaw is higher than in Ametrida. 
3 Since our knowledge of the genus is as yet imperfect, I have thought it best to give 
the characters of Ametrida centurio as gleaned from Peters. It is as follows: poste- 
rior palatal border scarcely incised ; basicranium very small, not so wide as the cochlear 
exposure; anterior temporal crest marked; interfemoral membrane incised; general 
coloration of the fur brown. 
PROCEEDINGS B. S. N. II. 
VOL. XXVI. 
16 
MAY, 1894. Allen. J 
242 
[Feb. 21, 
The characters of the head, ears, nose-leaf, and even the gland- 
like swelling on the front of the thorax, are as in A.' centurio. 
The warts on the lower lip are six in number instead of seven as 
in that species. In comparison with the figure given by Dobson 
they are not well defined. The markings of the wing membranes 
are as in other species of Stenodermatidae, excepting that the 
mesopatagium is furnished with eleven long, nearly vertically 
disposed muscle-lines which converge to a single point near the 
forearm. 
The terminal cartilages are filiform. The pigment is absent in 
the first and second digital interspaces. 
The gland-mass at the other side of the nose-leaf is raised on a 
skin fold as in Ectophylla. The glands, three in number, are 
lodged well up on the face and occupy a groove between the eye 
and the nose-leaf. 
Teeth. Peters in his description of Ametrida centurio describes 
a small "basal cusp" on the maxillary central incisor, and a 
bilobed minute lateral incisor; the lower premolars are not of the 
same form and size, the second being smaller than the first. 
These characters are not found in A. minor, in which species the 
superior lateral incisor is nearly half the length of the central. 
Dobson gives a description to which the teeth of the new species 
conform for the most part, but I find the intervals between the 
maxillary centrals too great to accept the statement that the teeth 
fill up by their bases the wide space between the canines. I infer 
that the London and Leyden specimens are not so much alike as 
are the London and the Boston examples, so far as the characters 
of the teeth are concerned. 
Rugae two in number; the rest of the hard palate being occu- 
pied with minute mammilations as in Sphaeronycteris. Fur 
above including the head is of a dull white ; the hair is long, the 
extreme tip and base having a delicate shade of brown. Beneath, 
a conspicuous patch pure white in color lies on the ventral aspect 
of each shoulder. A covering of short hair is seen on the wing 
membrane extending from the trunk to the distal third of the 
humerus and almost to the knee. This distribution is noteworthy 
from the fact that it is not distinctive from that of the back of the 
trunk, but the hair in the region just named extends upon that of 
the wing membrane so that no limitation between the trunk and 
the membrane can be detected. The fleshy part of the forearm i894-] 
243 
[Allen. 
is sparsely furred. The rest of the membrane is naked except 
the inferior border of the wing membrane where a delicate fringe 
of hair is seen. The remainder of the ventral aspect is much 
darker (with tawny brownish shades prevailing) than on the back ; 
the hair toward the side of the trunk (mammary line) is much 
longer and deeper in shade than elsewhere. The hair is uni- 
colored. It extends in an abruptly defined, sparse layer on the 
wing membrane as far as the end of the fleshy part of the forearm 
and to the wing membrane just beneath it and thence obliquely 
downward and inward to the knee. 
The dorsal aspect of the interfemoral membrane, the thighs, and 
legs are covered with hair. This is sparse over the limbs, but 
better developed over the membrane, especially at the middle 
third.1 The under surface is nearly naked but the thighs are 
thickly furred in a manner unusual in the family. The abruptly 
bent metacarpal bone of the second digit is the most striking char- 
acter in the skeleton. The penis is not pendant but directed 
upward parallel to the abdomen. The prepuce is half withdrawn 
from a subconical glans. 
MEASUREMENTS. 
A. minor 
A. centurio? 
Head and trunk 
35 mm. 
40 mm. 
Head 
13 
15 
Ear, height of 
11 
Tragus 
4 
4 
Nose-leaf height 
7 
" width, under part 
5 
Length of trunk 
26 
Forearm 
24 
32 
f thumb 
9 
1st digit -( metacarpal 
3 
( phalanx 
6 
I 9 
2d di-it / metacarPal 
14 
| phalanx 
6 
' metacarpal 
23 
29 
3d digit PbafanX 
8 
13 
11 
17 
3d 
7 
14 
1 The Leyden specimen is stated by Peters to be sparsely haired only on the inter- 
femoral membrane. 
2 Calculated from the English scale as given by Dobson. Allen.] 
244 
[Feb. 21, 
( metacarpal 
20 
20 
4th digit 
< 1st phalanx 
9 
10 
(2d 
12 
7 
f metacarpal 
21 
27 
5th digit 
(1st phalanx 
(2d 
8 
11 
10 
14 
Tibia 
13 
16 
Calcar 
4 
5 
Foot 
9 
8 
Since the above diagnosis was written out, I have made a 
detailed study of the skull. The division into metacephalic and 
mesocephalic portions is well defined, but the procephalic is 
absent. The brain case is greatly expanded, and the face is 
correspondingly narrowed. 
View from in front (noma frontalis, fig. 2.) The temporal 
Fig. 2. 
crest is faintly defined at anterior third of the sagitta. Posterior 
line is absent; the anterior line is trenchant and extends well 
down to the inner wall of the orbit where it is continuous with 
the orbital crest. The ridge at the position of the postorbital 
process as seen in some genera, as those of the Emballanuridae 
and in Pteropus leucocephalus, is bolder than elsewhere but is 
directed upward and outward rather than downward and out- 
ward. The two ridges diverge in such wise as to define a shield- 
like space on the frontal bone. The anterior nasal aperture is 
large, well carried up toward the orbits, thus showing the presence 
of small, broad nasal bones. The zygomatic arches are boldly 
expanded laterally. iS94-] 
245 
[Allen. 
The sides of the skull {norma fig. 3) show the pos- 
Fig. 3. 
terior half of the brain case sloping markedly toward the occiput, 
the superior semicircular line of which lies well down toward 
the base ; the bone below it inclining slightly toward the foramen 
ulagnum as in the pteropine bats. The anterior half of the brain 
case is convex, and the curve ends abruptly at the level of the 
ethmoidal foramen. 
The nasal bones project at the anterior nasal aperture ; the 
horizontal and ascending limb of the lateral borders of this aper- 
ture are about equal. The ascending limb is slightly oblique and 
concave. The upper border of the wide zygoma is rugose at 
the position of the ascending process. The alveolar border of 
the maxillary is nowhere horizontal but inclined upward and for- 
ward from second molar and upward and backward for the short 
distance answering to this tooth. 
The base of the skull {norma basilaris, fig. 4) exhibits a large 
Fig. 4. 
circular foramen magnum, a narrow oblique basilar process with 
deep lateral depressions. Tympanic bones small, half covering 246 
[March 7, 
Allen.] 
the petrous bone but in firm contact therewith. Zygomatic 
arches expanded and acutely bent. Pterygoid fossa not distin- 
guishable from the mesopterygoid ; a median ridge lies directly 
back of the exceedingly minute posterior nares. The hard 
palate wider than long and faintly incised between the scarcely 
produced palatines. The lower jaw possesses a high acute 
coronoid process. The condyloid process carried back slightly 
beyond the line of the angle which is deflected outward. . 
MEASUREMENTS OF THE SKULL. 
Length 
15 mm. 
Greatest width 
5 
Length of face from fronto-nasal junc- 
tion to the alveolar point 
4.50 
Bimalar breadth 
10 
Length of hard palate 
5 
Width of hard palate at the last molars 
4 
Glenoido-alveolar length 
6.02