36 PROF. HUXLEY ON SOME POINTS IN TUE 



On some points in the Anatomy of Nautilus pomjpilius. By T. H. 

 Huxley, F.E.S., Professor of Natural History, Government 

 School of Mines. 



[Eead June 3rd, 1858.] 



Some time ago my friend Dr. Sinclair, of New Zealand, had the 

 kindness to offer me two specimens of the Pearly Nautilus which 

 had been brought to him from New Caledonia, preserved in 

 Goadby's solution. I gladly accepted the present, and looked 

 forward to the dissection of the rare animal with no little plea- 

 sure ; but on proceeding to examine one of the specimens, I found 

 its anatomical value greatly diminished by the manner in which a 

 deposit from the solution had glued together some of the internal 

 viscera. Other parts of the Nautilus, however, were in a very 

 good state of preservation ; and I have noted down such novel and 

 interesting peculiarities as they presented, in the hope that an 

 account of them will be acceptable to the Linnean Society. 



Of the six apertures which, besides the genital and anal outlets, 

 open into the branchial cavity of Nautilus pompilius, one on each 

 side lies immediately above and in front of that fold of the inner 

 wall of the mantle which forms the lower root of the smaller and 

 inner gill, and encloses, the branchial vein of that gill. The aper- 

 ture is elongated and narrow, with rather prominent lips. It 

 measures about ^th of an inch. 



The other two apertures are larger, and lie at a distance of y^^ths 

 of an inch below and behind the other. They are in close juxta- 

 position, being separated only by a thin triangular fold of mem- 

 brane, which constitutes the inner lip of the one and the outer 

 lip of the other. 



The inner aperture is the larger, measuring y^^ths of an inch in 

 long diameter, and having the form of a triangle with its base 

 directed posteriorly. The outer aperture is not more than -i^th of 

 an inch long. The two apertures lie just above the edge of the 

 fold of membrane which runs from the inner root of the larger or 

 outer branchia, across the branchial cavity and beneath the rectum, 

 to the other side. 



These apertures lead into five sacs, which collectively constitute 

 what has been described as the pericardium. The sacs into which 

 the superior apertures open, by a short wide canal with folded walls, 

 are situated on each side of and above the rectum. Their inner 

 boundaries are separated by a space of not less than f ths of an 



