62 



z. The liver. 

 15. A branch of the anterior aorta wliich ramifies in the membrane con- 

 necting the two portions of the terminal fold of the intestine. 



19. The continuation of the posterior aorta along the dorsal aspect of the 



crop. 



20. Its bifurcation at the CESophagus, to form a vascular circle corresponding 



to the nervous circle round that tube. 



21. & 22. Arteries of the crop, gizzard, &c. 



PLATE V. 



Nautilus Pompilius, in the supine position, with part of the mantle removed to 

 expose the branchiae of one side, together with the heart and great vessels. 

 a. a. The mantle. 



h. One of the convexities produced by the ovarian gland. 



c. A section of the ovarian gland. 



d. The commencement of the posterior membranous siphon. 



e. The great shell-muscle of the left side. 

 /. The funnel. 



g. g. The lateral processes of the funnel. 

 h. The left crus or pillar of the funnel. 

 i. The infundibular valve, 

 fc. k. The digitations with the tentacles retracted. 



I. The outUne of the gizzard, indicating its situation, 

 m. The same of the ovary. 



n. The partition which separates the pericardivun from the peritoneal re- 

 ceptacles of the preceding viscera. 

 0. A bristle passed along the siphon through the orifice by which that tube 



communicates with the pericardium. 

 p. The larger branchia of the left side. 

 q. The smaller branchia of the left side; (those of the opposite side are 



concealed by the mantle.) 

 s. The common root or stem of the left branchise detached from the mantle. 

 t. The heart. 



