828 THE AMERICAN NATURALIST. | [Vor. XXXV. 
The usual position and appearance of nautilus in confinement 
are sketched in Fig. 6.1 It will be noted that the lower rim of 
the hood lies in approximately a horizontal position, the dorsal 
NNN i 
Fas. 6, 7, 8. — Diagrams showing the position of Nautilus at different stages of closing. 
fold of the mantle protruding slightly above the concave hinder 
rim, entirely concealing the black portion of the shell. The 
1 In the photograph which Willey has given (Q. 7. M. S. 1896, p. 179), the a 
ing specimen appears to be somewhat droopy, or perhaps it is just recovering 
from its alarm at being confined in so small a vessel, evidently a m 
Thus the base of the hood has shrunken away from the shell, es ially at the 
sides (but then this is not’ unusual) and the dorsal fold of the mantl 
normally rises to the upper margin of the black area of the shell can hardly be 
seen; the tentacles, too, sag down in a way which I think rather uncustomary, 
cramped, perhaps, by the smallness of the glass vessel. y impression, t00, -* 
that they have drawn down the ventral lip of the shell somewhat lower than 1$ 
usual. w easy it is, though, to criticise a zoólogical result, even in the form 
of an admirable photograph, and to forget that it may have been my own speci- 
mens that were sickly! 
