TURBO. TURBAN. 227 



I. Flat, and resembling the Helix, 86 to 92. 



8ti. Turbo Calcar. Rowel Turban. 



Montagu, pi. 29. f. 3. 



Shell flat, pale pink: spires four, depressed on the upper 

 side so as to "form a Hat hut not a sunken -surface, with 

 about thirteen large smooth lanceolate spines round the 

 body volution and part of the second, which radiate in 

 straight 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 lona : very 

 rare. 



87. Turbo cristatus. Crested Turban. 



Helix cristata. Montagu, Vignette, 1. f. 7,8 Walker, 

 f. IS. 



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 

 four, 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. depressus, and T. serpuloides, in its 

 close and regular striae. 



Ditches and watery places, v.v. 



88. Turbo Nautileus. Nautilus Turban. Fig. 78. 

 Linn. Trans, viii. pi. 5. 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 annulations, and sometimes with a small transverse 

 ridge which frequently shoots into spines and forms a kind 

 of crest on the back ; 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 



