436 Savage and Wyman, External Character, 
The two articulating surfaces on the upper extremity of the 
tibia are situated on different planes, the internal, the lowest 
is concave, and the external convex. The depressed concave 
surface corresponds with the longer condyle of the femur, so 
that the one compensates for the other, and when the bones 
are in place their axes are very nearly in the same line, The 
tibia is more cylindrical than in man, and is destitute of the 
ridge separating the internal and posterior faces. 
HI. GENERAL REMARKS. 
From the preceding descriptions there can be no reason 
to doubt that the Engé-ena is specifically distinct from the 
Enché-eco or Chimpanzée, the only member of the sub-genus 
Troglodytes hitherto recognized by naturalists. From the 
Enché-eco it is readily — 
1. By its greater size ; 
. 9. By the size and forth of the superciliary ridges ; 
* 3 M the existence of the large occipital and interparietal 
| crests e males, and by rudiments of the same in the 
4 By the great strength and arched form of the zygomatic 
arches ; 
5. By the form of the anterior and posterior nasal orifices ; 
6. By the structure of the infra-orbitar canal ; : 
7. By the existence of an emargination on the posterior 
edge of the hard palate ; x 
8. 'The incisive alveoli do not project beyond the line of 
the rest of the face as in the Chimpanzée and Orang; e 
9. The distance between the nasal orifice and the edge - P. 
the incisive alveoli is less than in the Chimpanzée ; 
» Dr. 
1 Prof. Owen estimates the height of the Chimpanzée at “ about y four cag de feet — 
m Savage gives as the result of the measurement of four adults, that two were 366.) i 
En ies , and two “five feet nearly.” (See Bost. Journ. Nat. Hist «Vien compared s 
ments of the Engé-ena given in the subjoined table, ' be for 
ahi riri ones ot the Enché-eco, will j justify the assertion that 4. 
must Ed TAM. 
