TURBO. TURBAN. 207 



by liner longitudinal lines, but hardly distinctly reticulate : 

 aperture orbicular, the margin thin and faintly marked by 

 the outer striae ; pillar-lip reflected, forming a slight per- 

 foration behind it : length five-eighths of an inch j breadth 

 three-eighths. 



In woods, and at the roots of fern. Near Sidmouth, in 

 Devonshire, they are found imbedded in the chalk cliffs, in 

 a kind of fossile state ; probably having been formerly 

 washed down, and gradually buried in the cretaceous soil. 



34. Turbo fontinalis. Stream Turban. 



Montagu, pi. 22. f. 4 Donovan, pi. 102 Dorset Cat. 

 pi. 18. f. 3, 4 Walker, f. 56. 



Shell slightly conic, rather depressed and obtuse at the 

 tip, thin, transparent, horn-color : spires five, much rounded 

 and deeply divided, slightly wrinkled or striate longitudi- 

 nally, with often the appearance of a few faint circular 

 ridges on the larger volution : aperture quite circular, at- 

 tached to the body volution at one point only ; the margin 

 very thin, a little reflected at the pillar, behind which is a 

 large and deep perforation : length sometimes a quarter of 

 an inch, and as much broad. 



In canals, and slow streams, v. v. 



E. TJic spires cross-barred, or reticulate. 35 to 56. 



35. Turbo Clathrus. False JVentletrap. 



Lister, pi. 588. f. 51 -Pennant, pi. 84. f. 2 Da Costa, 

 pi. 7. f. 11 Donovan, pi. 28 Dorset Cat. pi. 15. f. 11. 



Shell tapering to a fine point, thin, transparent, white 

 with sometimes obscure brown transverse markings : spires 

 ten or twelve, very much rounded, and so deeply divided 

 that they appear connected by the bars only which tra- 

 verse them ; these longitudinal bars are ten or twelve in 

 number, running rather obliquely from the base to the tip, 

 much raised, sometimes a little rounded, but mostly thin 

 and membnmaccous, and placed at rather remote but equal 

 distances : the interstices between them quite smooth and 

 .polished : aperture roundish-oval, thickened at the margin 

 T2 by 



