BOAS. 165 



beneath the skin. The accompanying engraving 

 exhibits these appendages as they appear exter- 

 nally in the Boa of Jamaica {Chilahothrus inor- 

 natus, DuM.), and the bones of one dissected out 

 of the flesh. Dr. Mayer considers that this spur 

 or hook is a true nail, in the cavity of which 

 is a semi-cartilaginous bone representing the last 

 joint of a toe ; this is jointed to a small bone 

 representing the metatarsus, the little projection 

 from the swollen joint above is the tarsus, and 

 the slender bone above is the tibia or leg-bone, 

 imbedded in the muscles, and terminated by 

 a slender curved and pointed filament of carti- 

 lage jointed to it, which probably represents the 

 evanescent rudiment of a femur or thigh-bone. 



The muscles of these enormous reptiles are 

 very numerous, and their power immense, when 

 exerted, as it is, for the purpose of depriving 

 their victims of life, in the constrictions of the 

 great coils or knots of the lithe body around 

 the prey. The strong bones of large quadrupeds 

 twined in the fatal embrace of one of these 

 Serpents are broken to pieces in a moment by 

 the irresistible pressure, which is not relaxed 

 till the last motions of life have ceased in the 

 miserable victim. 



The mode in which the Boadce seize and 

 swallow their prey, is graphically drawn by Sir 

 Robert Ker Porter, in a letter which accompanied 

 a noble specimen of a South American species 

 to the United Service Museum. The species 

 is supposed to be Boa scytale (Linn.), and is 

 nineteen feet and a half in length. After men- 

 tioning that by the colonists it is known by the 

 names of Water-Serpent, and Deer-Swallower, the 



