Litorina.] GASTROPODA. 187 



persons in gathering it. It is extensively distributed by English fisher- 

 men over the oyster-beds, in order to keep them clear of seaweed. 



Vernacular Name. -Periwinkle. 



About 150 species have been generally admitted, inhabiting all 

 parts of the globe. 



Fossil they are rather numerous, commencing with Secondary 

 forms ; there are also some older fossils of somewhat problematical 

 position, which may perhaps belong in the family. 



Sect. 1. MELARAPHE, Muehlfeldt, 1828. 



Melaraphe, Mhfdt.. in Menke, Synopsis, 1828, 23. Type : L. scabra, L. 

 Littorinopsis, Moerch, 1876, Mai. Blatt., xxiii, 135. 



Shell thin, imperforate ; spire acuminate, whorls flattened, usually 

 spirally striated, and adorned with coloured markings ; aperture 

 effuse anteriorly ; coluniella excavated. 



KEY TO SPECIES. 



A. Shell small, banded with white and blue, finely and narrowly 



spirally striated . . . . . . . . . . mauritiana. 



B. Shell somewhat larger, brown, with more distant spiral strife, 



which are whitish . . . . . . . . . . cincta. 



1. Litorina cincta, Quoy and Gaimard, 1833. Plate 38, fig. 27. 



Litorina cincta, Q. & G., Voy. Astrol.. ii. 1833, 481. pi. 30, f. 20. 21 ; Reeve, 

 Conch. Icon., x, f. 53. L. anyuh'fera, Gould, Otia Conch., 1846, 55. 

 L. luctuosa, Reeve, Conch. Icon., x, f. 65. 



Shell small, ovate-conical, imperforate, solid, slightly glossy, spirally 

 striate. Sculpture consisting of very little impressed spiral grooves, 

 the interstices much broader, but narrower on the base, crossed by 

 numerous fine and oblique growth-lines. Colour brown, grooves 

 yellowish-white, columella light brown, mouth dark brown, with 

 narrow short yellowish bands on the outer lip, and a broad whitish 

 band below. Epidermis rather thin. Spire conical, sharply pointed, 

 about the same height as the aperture, outlines slightly convex. 

 Protoconch acute, conic, of 3 slightly convex translucent and smooth 

 whorls. Whorls 6^, first slowly, then rapidly increasing, moderately 

 convex, the last subangled below the periphery ; base flatly rounded. 

 Suture well marked. Aperture oblique, oval, angled above. Peri- 

 stome sharp, not thickened. Columella subvertical, slightly concave, 

 much flattened and excavated below, where it bends off toward the 

 basal lip. Operculum of about 3 whorls, nucleus excentric. 



Diameter, 9 mm. ; height. 13-5 mm. (type). Diameter, 13-5 mm. : 

 height, 20 mm. (large specimen) : angle of spire, 46. 



Dentition. Hutton, T.N.Z.I., xiv, 164, pi. 7, f. D. 



Type in the Mus. Hist. Nat., Paris. 



Hab. Throughout New Zealaiid, but more common in the south. 

 Chatham and Snares Islands. 



