LAMELLARIA. 235 



the lingual apparatus. According to Macdonald the 

 genera Bro^vnia of D'Orbigny, Echinospira of Krohn, 

 and Calcarella of Souleyet, as well as his own genus 

 Jasonilla, are the young of exotic species of Lamellaria. 

 Lamarck^s genus Sigaretus has an external and opercu- 

 lated shell, and belongs to the NaticidcB ; it was founded 

 on the Sigaret of Adanson, being the Helix haliotoidea 

 of Linne. A great deal has been written on the histo- 

 rical part of this subject, with more or less correctness. 

 I do not claim any merit for endeavouring to elucidate 

 it ; nor, while making the attempt, do I feel that I incur 

 the satirical reproach of Persius : — 



Scire tuum nihil est, nisi te scire hoc sciat alter ; 



which Gilford renders, 



" Is science only useful as 'tis shown, 

 And is thy knowledge nothing if not known ? " 



Lamellaria perspi'cua"^, Linne. 



Helix perspicua, Linn. S. N. p. 1250. L. perspicua, F. & H. iii, p. 355, 

 pi. xcix. f. 8, 9, and (as L. tentaculata) f. 10; (animal) pi. PP. f. 1 and 

 (as the last-named species) f. 2. 



Body varying greatly in colour, which is sometimes lemon 

 with oval clear specks or else tessellated with milk-white, hght- 

 yellowish mottled with reddish spots and a few white flakes, 

 orange or whitish with orange blotches interspersed with flake- 

 white spots, or in other cases reddish-brown or umber speckled 

 with a few irregular yellow dots, which are darker in the centre: 

 mantle thickly stndded with large and coarse roundish-oval 

 warty tubercles or pustules of nearly the same size, each sur- 

 rounded by a border of flake-white and having a small dark 

 speck in the middle; underneath are two lobes which fold 

 nearly halfway over the foot : pcdlial sinus narrow, deep, and 

 short : snout semicircular and thick, cloven at the point, and 

 projecting beyond the foot: tentacles awl-shaped, rather long, 

 slender, and finely pointed, slightly scalloped at the edges, 

 diverging at an angle of about 30°; they are never carried 



* Transparent. 



