298 trochiDjE. 



Voyage. It may have been the present species; but 

 the operculum is stated to be testaceous. 



2. T. Gucenlan'dicus*, Chemnitz. 



T. gronlandicus, Chemn. Conch. Cab. v. p. 108, t, 171. t 1671. T. un- 

 dulatus, F. & H. ii. p. 528, pi. lxviii. f. 1,2, and pi. lxxiii. f. 5, 6. 



Body creamcolour with a few light-purplish-brown streaks 

 along the back and sides : pallial lappets small and thin : head 

 broad, notched or divided into lobes at the front edge (as in 

 T. helicinus), and furnished with a thin veil or hood in front : 

 tentacles extremely slender, and continually in motion ; tips 

 blunt : eyes on short but prominent stalks : foot large, broad 

 and somewhat truncated in front, bluntly pointed behind ; tail 

 keeled and having an eye-like tubercle at its extremity : ap- 

 pendages from 5 to 7 on each side, with an equal number of 

 ocelli, one at the base of each filamental appendage. Every 

 part of the body, except the snout, is ciliated in the most 

 exquisite manner. 



Shell having a rounded contour, rather solid, opaque, 

 somewhat glossy : sculpture, several narrow thread-like but 

 not much raised spiral ribs, or occasionally a few impressed 

 striae on the upper side, and more numerous and fine stria? on 

 the under side ; the surface is also covered with microscopical 

 and close-set transverse stria?, and below the suture of each 

 (especially the last) whorl it is puckered or marked with short 

 and curved folds in the same direction : colour yellowish-red 

 or fleshcolour : spire moderately raised : whorls 6, rather 

 tumid, gradually increasing in size : suture rather deep : mouth 

 slightly angular above : outer lip thin and flexuous : inner lip 

 thickened and angulated below, folded back over the pillar 

 and umbilical cavity above : inside purplish and iridescent : 

 umbilicus narrow, deep and obliquely angulated outside, ex- 

 posing all the spire : operculum having from 10 to 12 volu- 

 tions, which are separated from each other by a slight ridge. 

 L. 0-2. B. 0-25. 



Var. 1. albida. Shell of a whitish colour. 



Var. 2. dilatata. More depressed and expanded at the 

 sides, encircled on the upper part by only a few spiral strice 

 or impressed lines. 



* Inhabiting the seas of Greenland. 



