184 ME. r. E. BEUDAED— CONTEIBUTIONS TO THE 



aspects ^, which enables one to get a very good idea of its principal characters, even 

 without reference to the careful description in the accompanying letterpress. Judging 

 from the figures, it seems to me that T. auhryi docs not differ so much from T. niger 

 as does T. calvus. In the test MM. Gratiolet and Alix do not call attention to 

 any points of difference between their species and the Common Chimpanzee, except as 

 regards the teeth. I have pointed out, on pp. 182, 183, the main cranial characters of 

 Troglodytes calmis which seem to distinguish it from Troglodytes niger: none of these 

 characters are shown in the illustrations of the cranium of Troglodytes auhryi; in the 

 regular slope of the face (shown in the lateral view, I. c. fig. 4) and in the regular and 

 narrow palate the skull of this ape precisely resembles that of the typical Troglodytes 

 niger. 



Another " species " of Chimpanzee was described nearly forty years ago by Duvemoy ^ 

 in a paper dealing with the Anthropoids in general. This Chimpanzee was called 

 T. tschego, and the whole skeleton is described and for the greater part illustrated. 

 With regard to the skull, which measures in extreme length 20 cm., and is therefore 

 larger than that of " Sally," 1 cannot make out either from the description or from 

 the plate (plate vi.) any marked differences from T. niger. This species having been 

 identified by some with T. calvus, I naturally paid attention to the differences indicated 

 by Duvemoy in order to see how far the characters agreed with those of the animal 

 described in the present communication. One of the characters upon which Duvernoy 

 lays some stress is the fusion of the temporal crests in T. tschego and the separation of 

 those crests in T. niger. This supposed difference is indicated in the plate accom- 

 panying Duvernoy's memoir. With regard to this matter, one cannot dissent from the 

 opinion of Geoffrey St.-Hilaire^, who wjites : " Les caracteres osteologiques que donne, 

 a I'appui, M. Duvernoy, sont-ils veritablement specifiques ] Ke peuvent-ils s'expliquer 

 par de simples differences de sexe et d'age ] " The skull of T tschego showing the 

 convergence and junction of the said crests is larger (and, having the complete 

 dentition, therefore older) than the skull of " Sally," in which these crests do not meet. 

 Hartmann mentions the single crest in the adult Chimpanzee without suggesting that 

 this is a specific distinction. He speaks also of the muzzle being enlarged in front, the 

 greater width of the palate in front, and states that the alveolar border of incisors and 

 canines forms " un arc assez bombe." I do not think that anyone will be disposed to 

 lay great value upon these characters, and at all events they do not indicate any par- 

 ticular resemblance to the skull of T. calvus. The plate does seem to show a rather 

 thicker supraorbital ridge ; but this is not probably by itself a difference of great 

 importance. 



' Loo. cit. pi. ii. figs. 1-4. 



' "Des caracteres anatomiqiies des grands Singes pseudo-anthropomorphes," Arch. d. Mus. t. viii. 



' " Description des Mammiferes noureaux ou imparfaitement connus," &c., Arch. d. Mus. t. x. 



