Dr. Tuiton on the Genus Lacuna. 191 



Turbo paUididus. Turton, Diet. p. 192. 



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



four wcll-defmcd volutions ; and the aperture has a rather 



square outline. 



2. L. Mont (ten ti, tcsid subglobosd, scmipcllucidd, efusciald: spira 



subproductd : upcrturu rotiindalu. 

 Shell somewhat globular, semitransparcnt, 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. 



3. L. PuteoluSf testa seniioblongd, obliqud, purpurea, fasciis 



tribus obscurioribus : apcrtura ovali-rotundutd. 



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 Putcolus, 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. quadrifasciafa, testa conicd, fasciis quatuor ochraceis ; an- 



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 carinatcd 



appearance of the larger volution. 



