.'MO TROCHIDyE. 



The T. alabastrum may be a development of the T. zizi- 

 phinus, from climate ; it is a Zetland production. 



The T. conulus of Linnseus, Turton, and Donovan is exotic ; 

 what passes for it in British collections is usually a slender, 

 turreted, elongated variety of T. ziziphinus. 



** Discoidal, subdepressed, umbilicated. 



T. MAGUS, Linnseus et Auct. 

 T. magus, Brit. Moll. ii. p. 522, pi. 65. f. 6, 7 ; (animal) pi. D.D. f. 3. 



Animal inhabiting a subdepressed, subturriculated, conical, 

 coarsely striated tubercular shell of 5-6 tumid volutions, 

 lineated with oblique red-brown lines. Mantle even, except 

 that on the right side there is often seen an incomplete 

 tubular branchial fold. The head is a short muzzle, finely 

 crenated at the upper part of its semicircular termination ; it 

 is adorned with two suboval, approximating, large and long 

 head-lappets, with white fimbriated fringes at their edges, 

 which often hang over the head ; their colour above is pale 

 sulphur-yellow, beneath, striated with vivid pink blotches on 

 a greenish-yellow ground ; the neck on each side is pale pink ; 

 the muzzle, on the upper part, is branded with dark transverse 

 lines, and is studded, where the head-lappets do not interfere, 

 with five short, thick, distinct white setse ; the buccal disk is 

 yellow. The tentacula are long, rounded, basally tumid, sub- 

 conical, gradually becoming filiform and pointed ; the ground 

 colour is white, ringed more conspicuously on the upper than 

 on the under surface with a compound colour of purplish- 

 brown. The eyes are of turquoise blue, with black pupils, fixed 

 externally on distinct, orange-coloured, tumid pedicles. The 

 foot is a broad elongated oval, painted above with a mixture of 

 red-brown and yellow lozenges, arranged in shagreen fashion ; 

 the sole is yellow, partially marked anteriorly with an in- 

 distinct medial line, and has a fine white marginal fringe ; it 

 carries a well-expanded operculigerous lobe of the same colours, 

 similarly shagreened, ornamented with longer fringe than the 

 sole, and mottled with white and brown patches, having at 

 the margin, at equal distances, three longish, slender, filiform 



