576 PHILOSOPHICAL TRANSACTIONS. [aNNO 1682-3. 



Fig. 5. exhibits the head of the rattle-snake, with its mouth opened to show 

 his teeth, and other parts there. — a the hole of the nostril; b the foramen 

 which leads to a large cavity, which has no perforation for any nerve inwards, 

 but yet it is thought to be for hearing; cc the small teeth in the upper jaw,; 

 dd the large fangs, or poisonous teeth; eee the place where the bladders of 

 poison lay; f the larynx; g the forked tongue; h the teeth in the lower jaw; 

 i the place where the lower jaw is divided at the mentum. 



Fig. 6. represents the scull. — a the cranium without any sutures; bb the 

 orbits of the eyes; cc two small bones over the nose; d the gristly or rather 

 bony sepimentum of the nose; eea small bone that lies between the cranium 

 and that bone in which is fixed the poisonous fang; ff a cavity in that bone 

 to which is fastened the poisonous fang, whose outward orifice is represented 

 in the fifth figure by the letter (b) and is thought to be the ear; g the large 

 poisonous fang which is fastened to the ear-bone; h the other poisonous teeth, 

 which are not fixed in the bone but to muscles; ii the upper maxilla, which 

 contains the small teeth; kk one side of the lower maxilla, with its double row 

 of teeth, which in the middle seems to be joined by a suture; 1 the distance at 

 the mentum, between the two sides of the lower maxilla or jaw; mm where 

 the two maxillas are joined together backwards, and by a tendon are fastened to 

 another bone, which from its use, and for distinction sake, we call dilatores 

 maxillarum; nn the dilatores of the jaws; oo a short bone which joins the di- 

 lators to the scull or cranium ; p the vertebrae of the neck. 



Fig. 7. represents the poisonous teeth. 



Fig. 8. shows one of the vertebrae of the back. — sl the outward spine of the 

 vertebra, which is fiat longways ; b the inward spine of the vertebra, which is 

 round; ca large flat processus for the articulation of the vertebra; d small 

 transverse processuses for the setting on the ribs; e a round ball, like the head 

 of the OS femoris, which enters a socket of the lower vertebra, as that does 

 the acetabulum of the os ischii. 



Fig. g. shows one of the vertebrae of the tail. — a the spine towards the back; 

 bb the two inward spines; cc the transverse spines, analogous to ribs. 



Fig. 10. represents the vertebrae of the tail and the musculous flesh which 

 fastens the first rattle. — a the vertebrae; b the muscle on which is fastened the 

 rattle. 



Fig. 11. exhibits a single rattle, which has three joints: the first and largest 

 appears when conjoined with others, the two other serve for the fastening on 

 the succeeding rattle, and are covered by them. 



Fig. 1 2. shows the five rattles as joined together. 



