290 



- 



A. Mouth furnished with teeth and folds : outer lip sinuous 

 or notched : inner lip thickened. 



1. COCHLICOPA TRI'DENS*, Pulteney. 



Turbo tridens, Pult. Cat. Dors. Sh. p. 46, pi. xix. f. 12. Azeca 

 tridens, F. & H. iv. p. 128, pi. cxxv. f. 9. 



BODY greyish-slatecolour with a faint tinge of yellow, 

 closely covered with small black specks, which impart a 

 dusky or sooty hue, strongly wrinkled : mantle rather thick, 

 milk-white or greyish : tentacles somewhat transparent ; 

 upper pair very slender, with bulbs occupying about one- 

 fifth ; lower pair rounded at their extremities : foot long, 

 rounded in front and slightly projecting beyond the mouth 

 of the shell ; sides edged with white, and minutely speckled 

 with milk-white ; tail very pointed. 



SHELL subcylindrical or shaped like a chrysalis, nearly 

 transparent, very shining and of almost an opaline lustre, 

 light yellowish-brown with a tinge of red, faintly and indis- 

 tinctly wrinkled in the line of growth and marked with 

 extremely minute spiral lines, which are only perceptible by 

 the aid of a powerful lens : periphery rounded in the adult, 

 but sharply and strongly keeled in young specimens : epi- 

 dermis very thin : whorls 7, rather tumid, the last and pre- 

 ceding whorl being nearly of equal breadth, and much 

 larger in proportion than the others, which form a blunt 

 cone : spire produced, rounded at the point : suture slight, 

 with a transversely wrinkled border: mouth narrow, angularly 

 curved or channeled at the base and subtruncate in the 

 young, and also channeled at the upper angle ; it is still 

 further contracted by the teeth or plate-like folds which 

 are as follows : one principal fold on the pillar, which is 

 twisted round the inner lip, its crest sometimes notched, 

 and extends like a screw far into the interior, and there is 

 usually also a second small tooth or denticle close to the prin- 

 cipal fold and nearer the outer lip ; a strong fold winding 

 round the pillar lip, the end of which appears like a sharp 

 and prominent tooth ; and a sharp tooth-like tubercle on the 

 middle of the outer lip and placed on the inside edge of this 

 lip ; besides this last, there are occasionally two small and 

 scarcely perceptible denticles placed below it: outer lip 

 sinuous and (as well as the inner lip) encircled by a narrow 

 * Having three teeth. 



