Zoological Society. 71 



to the prominent nasal bones of Man made by any known species of 

 ajje — is as well-marked in the female Troglodytes Savagei as in the 

 male. The lower half of the coalesced nasals in Troglodytes Savagei 

 is expanded and nearly flat, of an oval form, with the border forming 

 the upper part of the nostril eraarginate on each side of a median, 

 sometimes bifid, point. Thus the lateral border of the nasal bone 

 describes a strong sigmoid curve, convex outwards in its lower two- 

 thirds, in Troglodytes Savagei; in the less expanded nasal bone of 

 Troglodytes niger the same border is usually concave outwards, or 

 very slightly convex outwards at the lower third ; and the outer 

 surface of the bone is flat or equably and very slightly convex. The 

 greater breadth of the lower end of the nasal with the expansion of 

 the upper ends of the premaxillaries, gives a diflferent form to the 

 external nostril in the Troglodytes Savagei to that which it presents 

 in Troglodytes niger : in this it is ovate or cordate with the narrow 

 end upwards ; in the larger species it is a wide ellipsoid, almost as 

 broad above as below. 



The alveolar portion of the premaxillaries in Troglodytes Savagei 

 was absolutely shorter than in Troglodytes niger, and therefore 

 much shorter relatively, and to that extent the skull of the larger 

 species is less ' prognathic* The zygomatic processes were not 

 only absolutely as well as relatively stronger and deeper than in 

 Troglodytes niger, but diflPerently shaped ; the squamosal portion 

 rising in an angular form in Troglodytes Savagei, and being as deep 

 as the malar portion. The temporal fossae are relatively as well as 

 absolutely wider ; for whilst the zygomatic arches are more expanded, 

 the diameter of the intervening postorbital part of the cranium is the 

 same in the male Trogl. Savagei as in the Trogl. niger. There is a 

 distinct hemispheric mastoid process in the male Troglodytes Savagei, 

 The spheno-maxillary fissure is narrower and less bent in Troglodytes 

 Savagei than in Troglodytes niger, in which it more nearly resembles 

 that of Man. The supraorbital ridges were even proportionally more 

 developed in the larger than in the smaller species of chimpanzee, 

 and send down a vertical prominence to the root of the nasal bones. 

 The outer and lower borders of the orbits, and the whole malar bones 

 are more prominent and tumid, and, with the enormous sagittal and 

 lambdoidal crests and zygomatic arches, give a scowling and dia- 

 bolical physiognomy even to dry bones of the head of this most for- 

 midable of the great Anthropoid apes. 



In the skull of the female of the Troglodytes Savagei in which 

 the canine teeth show the same sexual inferiority of size as in the 

 female Troglodytes niger, the molar teeth present the same superior 

 degree of development and complexity, especially the last molar, as 

 in the male of the larger species, and have demanded a concomitant 

 increase of bulk of the temporal muscles ; and consequently not only 

 are the zygomatic arches relatively stronger, but the temporal ridges, 

 instead of being separated as shown in an aged skull of the female 

 Troglodytes niger in the museum of the College of Surgeons,- by a 

 smooth tract of more than an inch in breadth, come into contact 

 at the beginning of the sagittal suture, and are so continued back- 

 wards with a narrow groove between them, to the lambdoidal crest. 



