. TAPIRUS. “99 
In the skull of a half-grown specimen of the latter species (retaining the milk-denti- 
tion), which was received by the Zoological Society from Corinto, and is preserved 
in the British Museum, the nasal region is as shown in fig. 3. The frontals form the 
greater part of the sinus-pits, and project considerably further forward in the middle. 
The nasals are small, thin, almost laminar bones; and each is divided by a transverse 
_ suture into an upper and a lower portion *, the former of which has a posterior process 
which forms part of the spiral central ridge of the sinus-pit. The mesethmoid is not 
yet ossified. 
The typical skull of 7. dow?, lent me by the United-States National Museum, is that 
of an adolescent female, with the last molar just coming up. As shown in fig. 4, the 
nasals are completely ankylosed with the frontals so as to be quite undistinguishable, 
although the interfrontal suture still remains open. The fused nasals and frontals 
expand abruptly in front of the sinus-pits, and are truncated in front, with a thin 
denticulated rounded edge, from beneath which the broad upper edge of the partially 
_ ossified mesethmoid projects forward. A drawing of the fronto-nasal region of a second 
typical skull of 7. dowi shows precisely the same conditions, as does also a sketch 
sent me by Professor Milne-Edwards of the skull in the Paris Museum which was 
figured, though not very satisfactorily, as that of T. bairdi by the late M. Gervais. 
In the British Museum there is also the skull of a fully adult, but not aged, animal, 
which was sent from the western part of Nicaragua by Captain Dow to Mr. Sclater, 
by whom it was presented to the national collection. Although most of the sutures of 
this skull are much more closed than in the Washington and Paris specimens above 
described, yet the ankylosis of the nasals with the frontals is not complete. The 
former bones are extremely small and thin, and they are separated throughout their 
length by the median projection of the frontals. Each nasal is divided, as in the young 
animal, into two portions. On the left side these remain distinct, but on the right the 
lower moiety has become fused with the frontal. The mesethmoid is fully ossified 
and its upper edge is greatly developed, embracing the fronto-nasal projection and rising 
in front to the level of its upper surface. Unfortunately this skull has been con- 
siderably injured, probably by the blows by which the animal was dispatched; and I 
have therefore preferred to figure another of the type skulls at Washington, which 
presents a very similar condition of the parts, and of which a careful drawing has been 
kindly supplied to me (fig. 5). Here the two parts of the right nasal are still separate, 
while those of the left have united, but neither of the nasals has yet ankylosed with the 
frontals. 
It will be seen from the foregoing descriptions that the peculiar characters of the 
fronto-nasal region in 7. dowi have now been verified in eight specimens of all ages, 
* Tn this skull the lower part of the left nasal has unfortunately been lost in preparation, but is restored in 
the figure. 
+ Journ. de Zool. ii. pl. 1. 
O 2 
