UNIVALVE SHELLS. 55 



Genus 28.— TURBO. 



Animal a Limax ; shell univalve, spiral, and solid ; aper- 

 ture contracted, orbicular, entire. 



The shells composing this genus are divided into five families : "wdth 

 the pillar-margin of the aperture dilated and imperforate ; **solid 

 and imperforate ; »**solid, perforated ; ****canceUated ;***»*tapering. 



Turbo rudis The Rustic Turbo. Plate IX. fig. 28. 



Sub-oval, faintly striated transversely, with five tumid volu- 

 tions; outer lip thick, glossy within; dull yellow, drab, 

 or fawn coloured; volutions separated by a deep suture. 

 Three-fourths of an inch long. Inhabits the British coasts. 



Turbo Terebra The Auger Turbo. Plate III. fig. 9. 



(Turritella terebra, Lamarck.) Taper, pointed, with twelve 

 or sixteen volutions, and numerous strong, spiral striae, the 

 intermediate spaces prominent and acute; white, reddish, 

 or cream coloured; one and a half inch long. Inhabits the 

 British seas. 



This figure represents the shell sectioned, to show the in- 

 ternal structure of the columella, f body, m m in columella. 



Turbo costatus. — The Ribbed Turbo. Plate III. fig. 



12. (Pyramis costatus, Brown.) Shell sub-pellucid, white, 

 and subturreted; volutions five, with prominent, longitudinal 

 ribs, a little oblique; apex obtuse; aperture suborbicular, 

 with a thick sulcated margin. 



Found on the coasts of Pembrokeshire, Dorsetshire, and 

 Northumberland. 

 RRRR Ribs. 



Turbo labiatus The Lipped Turbo. Plate III. fig. 



13. (Clausilia labiata, Lamarck.) Shell with nine re- 

 versed volutions or whorls, tapering to a fine point; colour 

 light brown, with strong, regular, longitudinal striae ; volu- 

 tions flat, and separated by a fine obsolete line; aperture 

 suborbicular and white, with a sinus at the upper end, and 

 two teeth -like laminae on the inner lip; margin reflected, 

 broad and thick. Found in Hyde Park, and the osier grounds 

 at Battersea in Surrey. 



