194 TURBO. TURBAN. 



very large and tumid, the others placed laterally but pro- 

 duced rounded and well defined : color yellowish-white or 

 inclining to purple, with various shades of green on the se- 

 cond and smaller volutions ; sometimes crimson, dull red, 

 or fulvous, often without bands, but generally with from 

 one to three deep purple or pale bands on the body volu- 

 tions, which do not extend to the remaining ones or in a 

 faint degree only ; the tip sometimes clear white, but al- 

 most always with a purple tinge : aperture ample, nearly- 

 orbicular: the outer-lip extremely thin, running nearly in a 

 straight direction at the base, by which the outer point at 

 the pillar-lip is somewhat angular : pillar-lip with a long 

 groove, and small but deep perforation : diameter about a 

 quarter of an inch. 



Montagu, at p. 151 of his Supplement, has erroneously, 

 we think, considered this shell as the young of Nerita rufa, 

 merely from the circumstance of having found it, probably 

 in a dead state, of a thicker consistence than that which he 

 had described as Helix Lacuna, at p. 428 of his work ; ac- 

 knowledging nevertheless that it differs from N. rufa, in 

 having the groove and the perforation placed upon the pillar- 

 lip, instead of the perforation being placed behind the pillar 

 as in all that genus, a difference which is never known in- 

 terchangeably to take place. We have examined very nu- 

 merous specimens, both alive and dead, collected in various 

 parts of England and Ireland, all corresponding with his 

 and our own descriptions, but exceedingly variable in colors 

 and markings ; and if we are in error, we must despair of 

 being able to procure the Helix Lacuna of Montagu. Da 

 Costa has well figured it, and admirably described it. v.v. 



4. Turbo quadrifasciatus. Four-banded Turban. 



Montagu, pi. 20. f. 7 



Shell somewhat conic, strong, semitransparent^ rather 

 obtuse at the point, white with a greenish tinge, covered 

 when, fresh with a slightly wrinkled skin, very minutely 

 striate transversely: spires four or five, rounded and well 

 denned ; the first very large, with a slight keel-like ridge 

 round the base, and generally four faint brown bands which 

 sometimes unite and form two broader ones ; on the next 

 volution are also often two bunds : aperture somewhat or- 

 bicular , 



