134 POPULAR BRITISH CONCHOLOGY. 



much expanded^ and the neck-lappet wide; it is 

 whitish, mottled and speckled with brown. 



T. umhilicatus : shell flat at the base ; outline of spire 

 rather swelled; surface spirally ribbed, grained, and 

 spotted with dark brown ; a hollow behind the colu- 

 mella. Animal of a dusky greenish tint. 



T. exiguus: shell narrow, small, conical, sometimes tawny, 

 sometimes crimson ; the wdiorls are edged with a belt, 

 and surrounded with three spiral crenated ribs. Animal 

 tinged with red. 



T. striatus : shell resembling T. exiguus, but closely grained ; 

 coloured with broad brown flames. 



T. Montagui : a small, speckled, long, conical shell, with 

 plain ribs, and crenated interstices. Animal white, 

 with black markings. 



T. tumid us : small, with a hollow behind the columella; 

 speckled, with plain, spiral ribs ; whorls swelled, and 

 with shoulders, so that the spire ascends by steps. 



T. cinerarius : shell with a central hollow, spirally striated, 

 marked with close g*rey lines. 



T. r/iagus, or tuherculatus : a broad shell, having a belt 

 round the lower, and a row of knobs on the upper part 

 of the whorls ; umbilicus large ; colouring variegated. 



