Mr. J. E. Gray on the Animal of Nautilus. 269 



natural situation — those of the body as they are seen through the 

 mantle. 



t. Tentacles. h. Hood or " disk." /. Funnel. 



m. Margin of the mantle. n. Nidamental gland. 



a. Adductor muscle, a c. Air-chambers and siphon. 



s. A portion of the outer wall of the shell, left to show the form and extent 

 of the black layer. 



Internal organs, indicated by dotted lines : — 



b. Branchiaj originating from the inner surface of the mantle and passing 



forwards into the funnel. 

 h. Heart and arterial glands. 



c. The crop. g. Gizzard. /. Liver. o. Ovary, 



The specimen is interesting as showing the large proportion 

 which the body of the animal (and the last chamber of the shell) 

 bears to the air-chambers. The mantle, as in the Gasteropodous 

 Mollusca, is of the same size and form as the mouth of the shell ; 

 its edge is entire and quite separate from the body, except at the 

 hinder part near the involute spire. The funnel is large and 

 quite separate from the mantle, which covers it partially, as is the 

 case with all other Cephalopods. Its lower part is continuous 

 like the free margin of the mantle, forming a ridge along the 

 side of the body under the eyes, and dilated behind into a half- 

 ovate flap, which lines the concavity of the disk, between it and 

 the posterior lobe of the mantle. This flap is well represented 

 by M.Valenciennes, t. 11. f. 3 A. 



If Dr. Loven's theory is correct, which I am inclined to be- 



