APLYSIA. 221 



8. Anterior Pedal Arteries (ant. ped. a.). Coronary of 

 Blatin and Vies. These paired symmetrical arteries form the 

 anterior termination of the aorta. They curve round the 

 lateral portion of the extreme anterior end of the foot and also 

 supply the anterior pedal gland. 



B. Gastro-oesophageal Artery (g. oes. a.). 



This large artery supplies that portion of the gut between 

 the oesophagus and the gizzard. In many forms it springs 

 from the abdominal aorta, but in Aplysiait arises independently 

 from the middle of the pericardial portion of the arterial trunk. 

 To trace its branches the main artery should be injected with 

 a coloured solution. On reaching the surface of the crop the 

 artery forks, the two arms of the fork running to right and left 

 of the crop along its surface and branching repeatedly, forming 

 a beautiful raised pattern when injected. A small branch is 

 given off to each salivary gland and runs along its inner side. 

 Backward branches ramify over the gizzard. 



C. Posterior or Abdominal Aorta (abd. ao.). 



This emerges from the left postero-ventral portion of the 

 pericardium and passes backwards to supply the organs con- 

 tained within the visceral hump. The artery runs dorsal to 

 the anterior coil of the intestine and soon gives off on the left 

 side a large branch to the liver. The hepatic artery divides 

 into superficial (s. hep. a.) and deep (d. hep. a.) branches which 

 ramify within the liver tissue. A second branch, also arising 

 on the left side, has numerous hepatic and intestinal branches 

 (hep. int. a.). It supplies the caecum (caec. a.), the artery 

 running along the concave side of the curve and giving off 

 branches over the surface of the caecum. The remainder of 

 the posterior aorta supplies the gonad and little hermaphrodite 

 duct (gen. a' .). 



