LAMELLARIA. 235 



the lingual apparatus. According to Macdonald the 

 genera Brownia 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 Naticida ; 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 Gifford renders, 



" Is science only useful as 'tis shown, 

 And is thy knowledge nothing if not known ? " 



C **r+%"*j 

 LAMELLARIA PERSPi'cuA*,ULinne.) j> U ) <j . 



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, light- 

 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 studded 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 : pallial 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. 



