204 



COMPARATIVE ANATOMY 



runs along the thickened edge of the mantle which concresces with the nnchal integu- 

 ment. Fi'om this vein spring nnmerons venous vessels which spread out on the 



Fui. 170.— Pulmonary veins, heart, and arterial system of Helix (after Howes). Tlie mantle 

 (roof of pulmonary cavity) is cut open and turned back. 1, Pulmonary vein (eflerent pulmonary 

 vessel) ; 2, kidney ; 3, auricle ; 4, ventricle ; 6, rectum, cut through ; 6, hermaphrodite gland ; 

 7, columellar nuiscle ; S, aorta visceralis ; ii, salivary glands ; 10, aorta cephalica. 



under surface of the mantle, i.r. on the roof of the mantle cavity, and there form a 

 delicate respiratory network. In tliis network the blood becomes arterial, and is 



Fic. 171. -Vascular system of Limax, afti>r drawings ocimbined Viy Leuckart frum Delle Chiaje 

 and Simroth. The veins carrying the venous blood out of the body into the lungs are black. 

 .1, auricle ; 1', ventricle ; VR, venous circidar sinus of the pulmonary cavity ; .-1j;, aorta cephalica ; 

 .1;/, aorta visceralis ; M, muscular stomach ; ZD, hermaphrodite gland ; H, digestive gland ; I, in- 

 testine ; JL, respiratory aperture ; A', arteria genitalis. 



next conducted thiough many vessels into the large puhnonary vein (vena pulmon- 

 aris), which runs back almost parallel to the rectum along the roof of the mantle 



