1881 . | 
229 
[Lucas, 
Simia satyrus Linn. Size under four feet. Male with no 
cheek protuberances. Skull of both male and female marked by 
two low — sometimes almost obsolete — ridges arising at the outer 
edge of orbits and running parallel or slightly converging from 
thence to back of skull. 
Simia Wurmbii Fischer. Size up to four feet six inches. 
Male with large cheek protuberances, female without them. Skull 
of male marked by two temporal ridges which converge and 
usually unite on parietal suture. Lambdoidal ridges prominent. 
Female under four feet and with temporal and lambdoidal ridges 
of skull much smaller than in male. 
Simia mono Owen. Founded on single skull. Incisors and 
canines small. Wide diastema between upper incisors and ca- 
nines. Temporal ridges low and converging. 
Simia sp. ? Wallace. Under three feet ten inches. Upper 
medium incisors very large in both sexes. Male with large canines. 
We can dispose of this last species by saying that all Orangs of 
medium age have very wide median ivpper incisors (11 to 14 
mm.) and that the canines of young males are proportionally 
larger than in old specimens. Moreover the size mentioned by 
Wallace is that of immature individuals. 
The characters assigned to S. morio by Professor Owen are com- 
mon to all skulls of old females and it is very evident that the 
species was based on the examination of an adult female skull. 
It now remains to consider the validity of S. Wurmbii to consider- 
ation as a separate species from S. satyrus, and for this purpose the 
number of skulls of each so called species placed at my disposal 
was as follows: Simia satyrus, seven males, eight females; Simia 
Wurmbii, six males, four females; Simia sp. ?, five young skulls. 
The last five were thrown out as too young for purposes of com- 
parison. The above series included most of those on which Mr. 
Hornaday based his article read before the Am. Assoc. Adv. Sci. 
in August, 1879, and as all were clean and nearly all perfect their 
characteristic points could be readily seen. As it was very impor- 
tant to have some readily recognizable characters from which to 
form an opinion as to the age of the various specimens, they were 
carefully studied for that purpose, and as a result the state of the 
spheno-occipital suture and amount of exposure of the roots of 
