Zoological Society. 231 
his return to America, together with a preliminary and highly inter- 
esting sketch of the natural history of the species by its discoverer, 
who proposes to call it Troglodytes Gorilla, adopting the term used 
by Hanno in describing the wild men which he discovered on the 
coast of Africa during his famous voyage”. . 
Dr. Wyman gives dimensions of the skulls of a male and female 
Troglodytes Gorilla, with comparative measurements of a character- 
istic skull of a negro, and those of the Troglodytes niger and Simia 
satyrus (Sumatran variety, or S. Abelii) from my Memoir in Trans. 
Zool. Soc. vol. i. p. 374; and he sums up the following points as 
showing that from the Troglodytes niger the Trogl. Gorilla “ is readily 
distinguished— 
©], By its greater size ; 
«<2. By the size and form of the supraciliary ridges ; 
«3. By the existence of the large occipital and interparietal crests 
in the males, and by rudiments of the same in the females ; 
«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 infraorbitar canal ; 
«7. By the existence of an emargination on the posterior part of 
the hard palate ; 
** 8. The incisive alveoli do not project beyond the line of the rest 
of the face, as in the Chimpanzee and Orang ; 
*©9. The distance between the nasal orifice and the edge of the 
incisive alveoli is less than in the Chimpanzee ; 
10. The ossa nasi are more narrow and compressed superiorly,” 
The 5th, 7th and 9th are the characters which are most decisively 
repeated in the Bristol specimens of the skulls of Trogl. Gorilla, and 
are those that are least ascribable to age or the operation of external 
circumstances tending to produce a stronger variety of Chimpanzee. 
The value of the character from size is established by the concurrence 
of the foregoing more fixed ones. The supraciliary ridges are rela- 
tively as strongly developed and as prominent in the skull of a female 
adult Trogl. niger as in that of the Trog/. Gorilla, and they are as 
angular and rough or uneven in the skull of the adult male Trogl. 
niger as in that of the adult male Trog/. Gorilla. ‘The male Trogl. 
niger shows also the median prominence between the orbits above 
the root of the nose. 
In six skulls of Troglodytes. niger Dr. Wyman found that ‘‘ the 
temporal ridges are generally separated from each other by a space 
varying from half an inch to one or two inches, according to age, 
but in none of them is to be seen even a rudiment of the interparietal 
ridge.” In an adult, but by the condition of the teeth, not old 
male Trogl. niger, the temporal ridges have met above the oblite- 
rated suture, and developed the rudiment of an ‘ interparietal ridge,’ 
which would probably have risen above its rudimental state had 
the exercise of the large temporal muscles been longer continued. 
* See the passage cited at p. 13, ‘Falconer’s Translation of the Voyage of 
Hanno,’ London, 1797. — P kes, 
