MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA. 143 



narrow behind, the outer lip thin, the inner reflexed; the 

 colour whitish, each turn with two subniarginal faint brown 

 bands. Length five-twelfths of an inch, breadth a fourth of 

 the height. 



Very similar to Eulima polita, but larger, stronger, and pro- 

 portionally broader at the base. 



Not uncommon in shell sand, from Cruden Bay. 



Turbo subiilatus. Donov. Brit. Sh. PI. 162. Helix subulata. 

 Mont. Test. Brit. Suppl. 142. Pkasianella subulata. Flem. Brit. 

 Anim. 301. Eulima subulata. Desh. Lamk. Syst. Ed. 2. viii. 455. 



GENUS 7. LACUNA. TURTON. 



Animal with the body elongated, spiral ; mouth pro- 

 boscidiform, with two thick lips, and a spiral filiform 

 tongue ; two slender contractile tentacula, bearing the 

 eyes on small pedicels near their base ; foot oval, broader 

 behind ; operculum horny, spirally marked. 



Shell ovato-conical, or subglobose, thin, with a deli- 

 cate horny epidermis, the spire short, the whorls convex, 

 rapidly enlarging, the last ventricose ; the apex rather 

 obtuse ; the aperture oval or roundish, the peristome in- 

 complete behind; the columella flattened, and forming 

 within the peristome an elongated groove continued 

 from the umbilicus. 



Nearly allied to Littorina and Phasianella, this 

 genus may at once be known by the groove from the um- 

 bilicus, bounded internally by the decurved margin of 

 the pillar. 



1. Lacuna vincta. Variable Lacuna. 



Shell ovato-conical, thin, semitransparent, with a delicate 

 epidermis ; the spire rather obtuse ; the whorls five, well sepa- 

 rated by the suture, moderately convex, glossy, obsoletely 

 striate transversely, with minute undulate longitudinal striulae ; 

 the mouth roundish-ovate ; the outer lip united nearly at a 

 right angle, very thin, the inner forming with the columella a 

 large obsoletely striate canal continuous with the pillar-cavity; 

 the colour various, generally whitish, or greenish-blue, with 

 four reddish-brown or chestnut bands on the last whorl, two 

 of them entering the mouth, two only appearing on the next 

 turn, and the apical turns uniform brown, more glossy, and 



