und Siriiicture of Ike Proteus Anguinus. 2D 



ing from it ; c, its bulb ; dd, the two primary trunks arising 

 from the bulb, and again subdividing ; e, the first branch 

 of the primary trunk, or artery corresponding to the com- 

 mon carotid, and which subdivides into two, one branch (y) 

 being continued to the first or exterior gill, and the other 

 \g) proceeding to the muscles of the os hyoides; h, the 

 vein which carries back the florid blood from the gill. 



The second branch of the primary trunk {d) soon also 

 subdivides, sending off" the branch (i) to the third gill, 

 and another (J) to the middle gill. To these two 

 branchial arteries, the two veins (mm) which carry 

 back florid blood, correspond. The principal trunk of 

 this second branch, after receiving this florid blood, 

 sends off" the artery (w), which, descending along the 

 air-tube, supplies the air-bladder and generative organs 

 in each sex ; it then curves upward, and from its cur- 

 vature gives off" the vertebral artery (o), which, after 

 sending some twigs to the occiput, enters the vertebral 

 canal, and descends along it : it also gives off" another 

 branch {p) to the temporal bone, and then making 

 another curvature downwards, it becomes a branch {q) 

 of the aorta, which, by uniting with its fellow of the 

 opposite side, it contributes to form. The aorta (r) 

 gives oflp the brajAchial arteries (jss), the mammary (u) 

 and the vessel t going to the stomach ; the letter x de- 

 notes a portion of the vena cava cut off". 

 Plate VII. Fig. 4. A leaflet of the gill highly magnified, ex- 

 hibiting the branchial artery (a), conveying dark blood to 

 the gill, and the branchial vein (h), returning florid blood 

 to the aorta. 



