230 
THE GEOLOGIST. 
ments, we see that the young orau-outan, gorilla, and chimpanzee 
have the transverse diameter of the skull proportionately equal,* and 
that the apparent length of the head in the chimpanzee is produced 
by the greater development of the supraciliary ridges than in the 
oran-outan. In the young gorilla, also an African ape, coincident in 
its geographical distribution with races of dolichocephalic ncgros, 
the transverse diameter actually slightly exceeds in Deslongchamps' 
5th plate that of the oran-outan. For all practical purposes of 
classification, however, it may be said that in youth, before the action 
of the biting muscles has altered the typical outward aspect of the 
brain-case, the oran-outan, gorilla, and chimpanzee exhibit skulls of 
which it cannot be predicted that each exceeds the others in the pro- 
portion of its transverse diameter. 
Professor Deslongchamps says, " Pour bien saisir les rapports, 
souvent caches, des etres entr'eux, I'etat adulte ne suffit pas toujours ; 
dans cet etat, ce sont surtout les differences qui se prononcent ; dans 
les premiers ages, les ressemblances sont plus accusees, les affinites 
sont moins masquees. 11 est utile, dans I'etude des animaux, d'imiter 
les botanistes, qui vont chercher les affinites des genres et des families 
des vegetaux dans les premiers rudiments des fruits, de la graine, de 
Tembryon, etc. Le groupe des singes anthropoides est remarquable 
entre tons par les changements, je dirais presque par les metamor- 
phoses, que subissent leurs tetes."t The comparison of the skulls of 
the anthropoid simiae in their young state, made by the cautious and 
philosophical Dean of the Faculty of Sciences at Caen, therefore, 
may be accepted as evidence against the hypothesis of the coincidence 
and derivation of the short and long-headed races of men with and 
from the alleged brachy- and dolichocephalic genera of Asiatic and 
African apes. 
The foregoing table is drawn up with a view to exhibit generally 
the number and proportions of extinct and existing mammalia which 
have been found in a fossil state in deposits where the remains of 
man have also been discovered. With no pretensions to complete- 
ness, it may yet serve as a convenient record, and may, to a certain 
extent, demonstrate the greater antiquity of e. g. the Abbeville beds 
as compared with the Danish Kjokkenmoddings, evinced by the 
greater proportion of extinct species in the former deposit. It must 
however be borne in mind that the mammalia of the Somme valley 
may not have attained a more northern range during the post- 
pliocene age, whilst boreal species existing in England and Denmark 
at the same time might leave no remains in post-pliocene strata in 
Gascony or Sicily. We know too little respecting the distribution 
of mammalia over limited areas in the later tertiary strata to entitle 
us to form any comprehensive generalization. 
In this table, 1 have made use of the researches of M. Lartet 
(Geol. Journal, 1860, p. 471 and 491, and Natural History Eeview, 
1862, p. 53) ; Mr. Prestwich (Geol. Journal, 1860, p. 189, and 
* Sur le Gorilla, par Professeur Owen, avec six planches ajoutees pai- Eudes Deslong- 
champs. 8vo. Caen. 1861. 
t Log. cit. p. 6. 
