830 THE AMERICAN NATURALIST. [VoL. XXXV. 
Appearance when retracting. — When a specimen is picked 
out of water (and it bears handling with considerable compo- 
sure) it slowly retracts, presenting the appearance shown in 
side view in Figs. 7 and 8, in three-quarter view in Fig. 9, in 
dorsal view Fig. 12, and in oral view Fig. 11. The first symp- 
toms of retraction are seen in the shortening of the tips of 
the tentacles and in the drooping of the hood. These processes 
an early stage of retraction. 
Nautilus resting and partly 
Figs. 10, 11, 12. — 10, Nautilus, front view, showing oral region, at 
I , Oral region at a lat t: f retraction. 12, D 1 t of 
g g , Dor p 
retracted, showing tentacles. 
are more or less rapid, depending upon the condition of the 
animal ; and I am led to believe that under normal circum- 
stances retraction can take place very quickly. In the short- 
ening of the tips of the tentacles the fleshy proximal portions 
become. notably stouter, at the same time more angular in 
section, dovetailing one beside the other so tightly that their 
common outer surface is flattened where it is later to be oppos 
to the inside of the shell. Observe also that the hood becomes 
notably depressed, at the same time exposing the dorsal rim of 
