70 Zoological Society. 
in this species occupy an extent of 2 inches 7} lines (0°068), whilst 
in Troglodytes niger their extent is only 1 inch 103 lines (0°048). 
The crown of the canine inclines more outwards.in Troglodytes 
Savagei; the longitudinal convex ridge on its inner surface is more 
prominent, the anterior groove bounding that ridge being deeper i in 
Troglodytes Savagei than in Troglodytes niger; the posterior inner 
groove is continued upon the root of the tooth in Troglodytes 
Savagei. ‘The last molar is more nearly equal in size to the penul- 
timate one, and is more complex in structure, than in Troglodytes 
niger; it has the posterior outer cusp and particularly the posterior 
inner cusp more developed, and it has distinctly the connecting 
cross ridge between the posterior outer and the anterior inner cusp, 
which ridge is not developed in the last molar of Troglodytes niger. 
The bony palate is longer in proportion to its breadth than in 
Troglodytes niger, in which the breadth of the palate between the 
canines is absolutely greater than in Troglodytes Savaget. 
The external sutures between the premaxillary and maxillary 
bones, which disappear so early in the 7vroglodytes niger, are more 
or less persistent and traceable in all but the oldest male skull of 
the Troglodytes Savagei; these sutures. show that after the pre- 
maxillary bone has entered the nose, of which it forms the lateral 
boundary of the external opening, it again appears upon the exterior 
surface of the face above the nostril, where its upper extremity forms 
a triangular or wedge-shaped flattened piece, interposed between 
the lower half of the os nasi and the os mavillare superius, thus ex- 
cluding the latter bone from the boundary of the external nostril. 
One skull of a young Troglodytes niger with deciduous teeth in place, 
shows by the still persistent upper half of its facial suture, that it 
terminates in a point a little above the middle of the border of the 
external nostril, and that a portion of the superior maxillary is in- 
terposed between it and the nasal: in two other skulls of young 
Troglodytes niger, the slender pointed summits of the premazillaries 
reach the nasals and exclude the maxillaries from the boundary of 
the nostril, but do not expand into triangular plates as in Troglodyies 
Savagei: in not any of the skulls of Troglodytes niger with the per- 
manent dentition does any trace of the suture between the PrORAR: 
illaries and maxillaries remain *. 
The nasal bones of the Troglodytes Savagei also afforded a re- 
markable specific character: although the traces of their primary 
median division were obvious at their lower part, they had coa- 
lesced with each other as in the smaller species; but instead of 
being flat, or slightly and equably convex en the anterior surface, 
as in Troglodytes niger, they are produced forwards as they incline 
towards each other, along their upper half, and project there in the 
form of a slight bony longitudinal ridge, equally dividing the lower 
half of the interorbital space. ‘This character—the nearest approach 
* M. de Blainville, describing the osteology of the chimpanzee from a young 
specimen of the Troglodytes niger, says, “* Mais les prémaxillaires, qui offrent la 
particularité de toucher a peine les os du nez et de souder de fort bon heure avee 
les maxillaires,” &e. Ostéographie, fasc, i. p. 33, ’ 
