Di'. Turtoii on the Genus Lacuna. 191 



Turbo paUidulus. Turton, Diet. p. 192. 



The spire of this species is quite flattened, consisting of three or 



four well-defined volutions ; and the aperture has a rather 



square outline. 



2. L. Montacuti, testa subglohosct^ semipelluctd&y efasciata: spirA 



suhproducta : aperturA rotundata. 

 Shell somewhat globular, semitransparent, without bands : spire 



slightly produced : aperture rounded. 

 Helix Lacuna, Montagu, 428. t. 13. f. 6. 



When deprived of its brown epidermis it is white in colour, or 

 shews various shades of purple or red, but always without 

 bands. 



S. L, PuteoluSy testa semioblonga, obliqud, purpure&y fascits 

 tribus obscurioribus : apertura ovali-rotundata. 



Shell roundish-oblong, oblique, purple with three deeper bands : 

 aperture roundish or oval. 



Cochlea parva, Da Costa, 85. t. 8. f. 12, 



Helix Lacuna, var. Montagu, 429. 



Nerita rufa, Dors. Cat. t 14. f. 12. 

 Montagu, Supp. 151. 



Turbo Puteolus, Turt. Diet. 193. 



Shell much thicker than the last, always marked with three dark 

 bands, and when full grown has the larger volution conside- 

 rably produced obliquely. 



** Spira producta, conoidea. 



Spire produced, more or less conoid. 



4. L. quadrifasciata, testa conica, fasciis quatuor ochraceis ; au' 



fractu majori basi subcarinato ; sulco columnari parvo. 

 Shell conical, with four ochraceous bands, the larger volution 



slightly carinate at the base : the groove on the pillar small. 

 Turbo quadrifasciatus, Montagu, 328. tab. 20. f. 7. 

 The bands are sometimes faint and nearly obliterated ; but the 



shell may always be distinguished by the slightly carinated 



appearance of the larger volution. 



