231 
The four species in the Museum, of different ages, from young to 
adult, scarcely vary from one another. | 
4. P. ausicans. (Pl. LXXXI.) 
Hair very long and loose; that of the head, neck, and upper part 
of the thighs whitish ; that. of the shoulders, back, sides, tail, and 
fore legs black, with short white tips ; on the hind legs, sides of the 
neck, inside of limbs, chest and belly, reddish. The hair of the 
head very long, covering a great part of the face. 
Young.—Hair of the head, neck, and shoulders very long (longer 
than in the adult), blackish near the roots, and on the under side of 
the body rather more rufous; the moustaches more distinct. 
Hab. Brazil; Upper Amazon (Mr. Bates). 
The following species appear to be distinct from the above :— 
1, Pithecia leucocephala, Geoffroy ; Kuhl, Beitr. p. 45, which 
the latter says is well figured as the Yarqué by Audebert (Singes, 6. 
sect. 1. f. 2), and which he describes thus :—‘“ Nigra ; capite albo; 
omnibus pilis corporis unicoloribus longissimis, caudalibus preesertim, 
capitis autem albis brevibus.” 
The young male, adds M. I. Geoffroy, “ différe de l’adulte par le 
ventre d’un brun roussiatre, le pélage tiqueté sur les parties latérales, 
et surtout par la téte revétue de poil en partie noir. Chez les 
adultes les poils de la téte sont entigrement d’un blanc lavé de jaune, 
qui passe au jaune sur les joues.” 
2. P. albinasa, Geoff. Cat. Mamm. p. 56; Arch. du Mus. v. 559. 
*«Espéce distincte dés le premier aspect, par son nez couvert de 
poil ras, dont la blancheur contraste avec le reste de la face et tout le 
pélage, qui sont d’un noir profond.”’ 
Hab. Para, Brazil. 
6. DescrirpTiION or A New Species or GEOCLEMMYS FROM 
Ecuapor. By Dr. J. E. Gray, F.R.S., V.P.Z.S., ere. 
(Reptilia, Pl. XXIX.) 
Mr. Cuming has lately sent to the Museum two shells of a species 
of Freshwater Tortoise, and a younger specimen, in spirits, of the 
same animal, obtained by Mr. Fraser at Esmeraldas, on the western 
coast of Ecuador. ( 
GEOCLEMMYS ANNULATA. (Pl. XXIX.) 
Shell oblong, subquadrangular, black, slightly and irregularly 
varied with yellow; the vertebral plates square, almost as long as 
broad, with a compressed flat-topped anterior keel, highest on the 
fourth vertebral plate, which is narrower behind ; margin sub-entire, 
with a triangular yellow spot on the under side of each plate ; nuchal 
