NAUTILUS. 119 
lines are not visibly raised: aperture half heart-shaped, 
very little clasping the body at the sides : minute. 
In fine and drifted sand: v. m. 
6 . Nautilus umbilicatulus. Perforated Nautilus. 
Mont apt, pi. 18. f. 1 —Walker , f. 69. 
Shell white, semitransparent, flat, perforated on both 
sides : joints nine or ten, raised and rather rounded, marked 
by radiating lines which are depressed: aperture clasping 
the body nearly equally on both sides : minute. 
In fine and drifted sand. v. m. 
i, Nautilus crassulus. Thick Nautilus. 
Montagu, pi. 18. f. 2— Walker, f. 70. 
Shell strong, flat, opake, pale brown, with a deep perfo¬ 
ration on both sides : joints numerous, close together, and 
raised above the line of separation: aperture a little oblique, 
hardly clasping the body, furnished with a syphon: minute. 
In fine sand. v. m. 
i Nautilus crispus. Crimpled Nautilus. 
Montagu, pi. 18. f. 5— Dorset Cat. pi. 19. f. 29— Walker , 
f. 65. 
Shell white, opake, perforated both sides, with a keel¬ 
like ridge on the outer edge : joints about twenty on the 
larger volution, flexuous and crenate, and marked by raised 
lines : aperture half heart-shaped, clasping the body, fur¬ 
nished with a small central syphon. 
In fine saud. v . ru. 
9. Nautilus Beecarii. Twisted Nautilus . 
Afonft/gtq pi. 18. f, 4— Dorset Cat. pL 19. f. 28 —IPilker , 
f.& 
Shell transparent, white or covered with a brown skin, 
crimson when the inhabitant is alive, convex on one side 
and flat on the other: spires four or five, twisted, with ten 
joint* in the first which are deeply grooved: aperture ob- 
oval : minute. 
Fumy. With the spires reversed. 
Montagu, pi, 18. f. 6— Walker, f. G4. 
Ouoysters,and seaweeds. v, v. 
J 10. Nautilus 
