beneath the skin. The accompanying engraving exhibits these appendages as they appear externally in the Boa of Jamaica (Chilabothrus inornatus 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 cartilage 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 Boadæ 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 mentioning that by the colonists it is known by the names of Water-Serpent, and Deer-Swallower, the
