390 PROFESSOR OWEN ON THE OSTEOLOGY OF 



and to procure a dead subject, which I shall preserve in spirits ; great uncertainty, however, attends my suc- 

 cess, as they are indescribably fierce and dangerous, and are found only far in the interior ; they are killed by 

 elephant-hunters only in self-defence. 



" Below you have a sketch of the cranium of the male and female*, executed for me by Mrs. Prince, the wife 

 of Dr. Prince, the English Baptist missionary at Fernando Po, who is here for a short time in search of health. 

 a a are two low ridges converging, as seen in the sketch, and uniting at x, and forming a strong prominent ridge 

 in the course of the sagittal suture, which comes into a junction with a lateral ridge (rf) sent back from the 

 petrous portion of such temporal bone : e is a strong fossa of triangular shape between the ridges a a. The 

 space between the zygoma and temporal bone in a transverse direction is one inch and three quarters deep ; the 

 diameter from before backwards three inches ; at 4 is a sinus about half an inch in depth and an inch in length, 

 with foramina for the passage of blood-vessels and nerves. The two upper middle incisor teeth are absent, but 

 their sockets show their size to have been nearly if not quite double the two outer ones. The two lower 

 middle incisor teeth are narrower than the two outer. The female cranium is a fuU-grown one, but ditfering 

 from the male in the prominence of the ridges : the two anterior corresponding to o a in the male and the 

 central are rudimental only, except at the extremes of the latter, where it joins the posterior transverse ridge, 

 lettered d in the male. It has lost the two middle upper incisors, which bear the same relation in respect to 

 size to the two outer that those of the male do. All the incisors, both in the upper and lower jaw, are larger 

 than they are in the male : the canines in the female are shorter than in the male. These points are all that I 

 need specify to enable you to identify the crania with any in your possession. You will greatly oblige me by 

 a compsunson, and communicating the result at your earliest convenience." 



I lost no time in making the coaiparisons and transmitting the results to m}^ esteemed 

 correspondent : they were in substance to the effect, that the skulls figured and described 

 in his letter, though resembling that of the great Orang of Wurmb in the development 

 of the sagittal and lambdoidal crests, and in the sexual difference in the development of 

 the canine teeth, differed plainly from it by the greater size and prominence of the 

 supraorbital ridge, and in that respect resembled the known Chimpanzee. As I had at 

 that time ascertained the characters of the adult dentition of a nearly full-grown male 

 Troglodytes niger, but had not seen a skull of the old animal, the superior size of the 

 canines to those in the female led me to suspect that the sagittal and lambdoidal crests 

 might acquire in strong and aged individuals the proportions of those represented by 

 Dr. Savage, and that thus the resemblance to the Pongo of Wurrab in this respect might 

 be manifested by the adult male of the Troglodytes niger. Without the means of 

 making a more detailed comparison, and in the absence of the skull of an old male 

 Chimpanzee (which by the kindness of my friend Mr. Stutchbury I have now been 

 enabled to describe and figure. Plates LVIII. LIX. and LX.), I could not feel satisfied 

 that the specimens alluded to by Dr. Savage had belonged actually to a distinct species 

 of Troglodytes. In the absence, therefore, of means of making comparisons of other 

 characters, besides superior size, larger canine teeth, and concomitant strong sagittal 

 and lambdoidal cristie, as these were indicated in the sketches transmitted, I deemed it 

 better to communicate my doubts to Dr. Savage than to hazard in the publications of the 



* Woodcuts of these figures are given in the abstract of the present memoir published in the ' Proceedings 

 of tlie Zoological Society," Feb. 22, 1848, p. 29. 



