TURBO. TURBAN. 
I. Flat, and resembling the Helix, 86 to 92. 
86. Turbo Calcar. Rowel Turban. 
Montagu, pi. 29. f. 3. 
Shell fiat, pale pink: spires four, depressed on the upper 
side so as to form a flat but not a sunken surface, with 
about thirteen large smooth lanceolate spines round the 
body volution and part of the second, which radiate in 
lines from the shell ; the base convex and perfo¬ 
rated: aperture orbicular: diameter a quarter of an inch. 
Found by Captain Laskey, on the island of Iona : very 
rare, 
8/. Turbo cristatus. Crested Turban. 
Helix cristala. Montagu, Vignette, 1. f. 7, 8— Walker, 
tut 
Shell flattish, semitransparent, light horn-color, rather 
glossy, often covered with a thin skin, very little sunk at 
the top, flat and perforated underneath: spires three or 
tour, very much rounded and deeply divided, finely and 
closely striate transversely: aperture quite orbicular, at¬ 
tached to but not clasping the body volution, the margin 
not thinner than the rest of the shell, and placed very little 
obliquely: diameter the tenth of an inch. 
It differs from T. depress us, and T. serpuloidcs, in its 
close and regular striae. 
Ditches and watery places, v.v , 
88. Turho Nautileus. Nautilus Turban. Fig. 78. 
Linn. Trans, viii. pi. 6. f. 4 —Dorset Cat. pi. 19. f. 16. 
Helix Nautileus. Montagu, pi. 25. f. 5— Walker, f. 20, 
21 . 
Shell flattish, semitransparent, horn-color, generally co¬ 
vered with a brown skin: spires three or four, hardly rising 
one above the other, furnished with distant elevated longi¬ 
tudinal annotations, and sometimes with a small transverse 
ridge which frequently shoots into spines and forms a kind 
of crest on the back j the base flat and perforated : aperture 
orbicular, as if abruptly cut off, not attached to the body, 
sometimes a little clasping the volution, and rarely drawn 
into a somewhat oval shape : diameter the eighth of an inch. 
Ditches and ponds, on the under surface of plants, v. v. 
89. Turbo 
