1871.] DK. J. K. CRAY ON THE HRADYl'ODl DM. 435 



broader than the rest. The others cylindrical, the hinder the largest. 

 The front upper grinder in the very young specimen is small and 

 conical when the other grinders in the upper and lower jaws are 

 well developed, being very different in this respect from the two- 

 toed Sloths or Cholcepi. The malar bone moderately short, with a large 

 inferior process and an elongated ascending superior process, which 

 is often more or less dilated at the end, especially in the genus 

 Bradypus. 



Bradypus. 



Bradypus, Gray, P. Z. S. 1849, p. 67. 



Pterygoid swollen, hollow, vesicular. Males and females similar. 

 Lower jaw with a short truncated anterior lobe varying in width at 

 the anterior end. Intermaxillary bone rhombic, as broad as long. 

 The angle of the lower jaw is broad, triangular, with a rounded lower 

 edge, and produced far behind the condyle (see skulls, P. Z. S. 

 1849, p. 65, t. x.). The lower ramus of the malar bone is simple, 

 elongate, triangular, and the upper ramus much produced and dilated 

 at the end. 



De Blainville figures a skull of a young animal under the name of 

 B. torquatus, t. iii. ; but the figure looks much more like the skull 

 of an Arctopithecus ; for it does not represent the peculiar dilated 

 appearance of the upper malar bone. 



The three nearly adult skulls of Bradypus in the British Museum 

 vary in the flatness or convexity of the front of the forehead, two of 

 them being rather narrow and concave between the orbits, and one 

 (see Bradypus crinitus, P. Z. S. 1849, t. x. f. 1) convex and wider. 

 I have figured the latter under the name of B. affinis in the ' Pro- 

 ceedings ' of this Society, 1849, t. x. f. 2, skull (737a). 



This skull (737«) which I have so distinguished differs in several 

 other points from the other two ; that is to say, it has a rather nar- 

 rower hinder opening to the nostrils, and the vesicular pterygoids, 

 instead of being broad and ovate, are narrow, as in 923a and b, 

 elongate, and compressed ; and 1 am inclined to think these indica- 

 tions of a distinct species, but they may be marks of the sex. The 

 nose is rather narrower. 



1. Bradypus crinitus. 



Skull rather concave between the eyes. 



Bradypus torquatus, Prince Maximilian, Abbildungen, t. (good 

 figure of female). 



Bradypus crinitus, Gray, P. Z. S. 1847, p. 67, t. x. f. 1 (skull); 

 and Cat. Edentata B. M. p. 364. 



Hab. Brazil, Para, Rio Janeiro. 



We have three specimens of this species in the British Museum — 

 one from Brazil presented by Lord Stuart de Rothsay, the others 

 without any precise locality, but said to be from South America. 

 They are very much alike, but vary in the length of the black nuchal 

 crest and in the intensity of its colour ; in the largest specimen it is 

 the shortest and of a brownish black colour ; none of the specimens 



