1861.] dr. gray on mr. du chaillu's mammals. 273 



5, Observations on Mr. Du Chaillu's Papers on "The New 

 Species OF Mammals " discovered by him in Western 

 Equatorial Africa. By Dr. John Edward Gray. 



Mr. Du Chaillu, in a maiden zoological paper in the ' Journal of 

 the Natural History Society of Boston,' for 18G0 (pp. 296 and 358), 

 describes fifteen species of Mammals, and gives a short notice of a 

 sixteenth, which he collected in Equatorial Africa, and which he be- 

 lieves to be undescribed. 



Iladng lately had the opportunity of examining these animals, I 

 am induced, in response to Mr. Du Chaillu's challenge, to lay before 

 the Society the following observations on them. 



I may observe that the determinations are founded on the com- 

 parison of the specimens named by Mr. Du Chaillu with typical spe- 

 cimens in the collection of the British Museum. 



Troglodytes calvus, sp. uov., Du Chaillu, Boston Journ. 

 N. Hist. 1860, p. 296 ; Travels, t. 32. p. 232, t. 48. p. 357, t. 63. 

 p. 422. ^ 



Troglodytes kooloo kamba, Du Chaillu, Bost. J. p. 358, 

 Travels, t. 39. p. 270, t. 49. p. 360, t. 50. p. 361. 



I have examined the skins of these presumed new species, and 1 am 

 not able to discover any character by which thev can be distinguished 

 from the common T. niger. Dr. Sclater and my assistant Mr. Ger- 

 rard have each examined the skulls and skeletons, and they inform 

 me that they have come to the same conclusion ; and I observe that 

 the writer of chapters 20 and 21 of Mr. Du Chaillu's 'Explorations,' 

 and Professor Owen, both speak of them as interesting varieties of 

 that species. The baldness appears to be only an individual pecu- 

 liarity of the specimen; the hair seems to have been worn off: the 

 skin, like most of the others, is in a very bad state. 



The common Chimpanzee has been described long ago as forming 

 a shelter of boughs and leaves ; so that it could not be a peculiarity in 

 the T. calvus ; and it is very doubtful if this does not arise from their 

 having been observed sitting under the shelter of some parasitic 

 plant, perhaps a Loranthus. 



Dr. Eranquet, in the ' Archives du Mus.,' is inclined to believe 

 that there are three species or varieties of the Chimpanzee. Mr. Du 

 Chaillu, in the paper above referred to, doubts the distinctness of 

 these, and believes Dr. Eranquet has described as distinct the old and 

 young of the common Chimpanzee. 



(See observations on Mr. Du Chaillu's figures of the animal in 

 •Ann. and Mag. N. Hist.' 1861, June, p. 463 et seq.) 



_ I may observe that one skull of an old animal in the collection 

 differsfrom the other Chimpanzee's skull in the lower edge of the 

 lower jaw being straighter and more at a right angle with tlie ramus 

 of the jaw, and in having the hinder angle rather more produced. 

 This makes the skull stand erect on its base, whilst the others are 

 inclined to fall backward on the condyles ; but this must be only an 



Proc. Zool. Soc— 1861, No, XVIII. 



