430 



narium terminates half-way from the external nostril. Two turbinals are attached to the 

 maxillary wall of the olfactory chamber, but the ethmo-turbinal is the least extensive, and 

 consists of a series of subvertical curved laminae of bone descending and radiating from the 

 inferior surface of the floor of the rhinencephalic chamber. There is a small lacrymal bone 

 wedged in between the frontal, maxillary, and malar, but no lacrymal perforation, nor is there 

 any antorbital foramen. 



Mus. Langstaff. 



The following are parts of the skeleton of the same Bradypus tridactylus : 



Mus. Lcmgstaff. 



2371. The nine cervical vertebrae. 



The pleurapophysis of the eighth cervical is anchylosed, completing the arterial foramen, 

 as in the seventh vertebra. If the diapophysis of the ninth vertebra supported the rudiment 

 of a rib, it has not been preserved. 



2372. The pelvis and caudal vertebrae. 



Neither the vertebrae of the sacrum, nor the elements of the os innominatum, have coalesced. 



2373. The right scapula, with the detached coracoid contributed to the anterior apex 

 of the glenoid cavity. 



2374. The right humerus. 



2375. The right radius, ulna, and bones of the fore-foot. 



The epiphyses of the long bones are not yet anchylosed to the shafts, nor are the proximal 

 phalanges of the three middle digits anchylosed to the metacarpals, of which they seem to 

 be the distal epiphyses. 



2376. The right femur. 



2377. The right tibia and fibula, with the bones of the right hind foot. 



Mus. Langstaff. 



The following preparations are from the bones of a Three-toed Sloth (Bradypus tridac- 

 tylus) : 



Presented by Copt. Sir Everard Home, Bart., F.H.S. 



2378. The right humerus, longitudinally bisected, showing the shaft almost wholly 

 occupied by a fine cancellous structure : the epiphysial sutures are not yet 

 obliterated. 



