56 LITTORINID^.. 



L. PALMDULA, Da Costa. 



Almost always broader than long, flattened beneath, peculiarly 

 expanded at the mouth : lacuna large in the adult, and equal to 

 two-thirds the length of the shell, sometimes absent in young 

 specimens. 



Plate LXXII. fig. 1, 2, and fig. 3, 4 (as jxitula). 



Nerita paUidula, Da Costa, Brit. Conch, p. 51, pi. 4, f. 4, 5. — DoNOV. Brit. 

 Shells, vol. i. pi. IG, f. 1.— Mont. Test. Brit. vol. ii. p. 468. 

 — Waton and Back. Trans. Linn. Soc. vol. viii. p. 226. — 

 Rack. Dorset Catalog, p. 57, pi. 20, f. 4, 5.— Dillw. Recent 

 Shells, vol. ii. p. 986.— Wood, Index Testae, pi. 35, f. 21. 



Turho pallidulus, Turt. Conch. Diction; p. 192, f. 24, 25, 85, 86. 



Naiica palUdula, Blainv, Faune Franq. Moll. pi. 14, f. 6. — Fleming, Brit. 

 Animals, p. 320. — Brit. Marine Conch, p. 1 50. — Brown, 

 Illust. Conch. G. B. p. 25, pi. 13, f. 18, 20. 



Laeuna „ Turt. Zoolog. Journ. vol. iii. p. 190. — Johnston, Berwick 



Club, vol. i. p. 270. — Macgilliv. Moll. Aberd. p. 145.— 

 Hanl. Brit. Marine Conch, p. xxxii. f. 85. 

 „ „ var. ? patula, Hanley, Brit. Marine Conch, p. xxxvii. f. 83. 



The broad canal and Natica-Y\\i(i aspect of this most 

 characteristic species of Lacuna readily enable us to sepa- 

 rate it from its ]3ritish congeners. It is flattened under- 

 neath, but above is almost hemispherically convex, and of 

 a somewhat obliquely subtriangular-ovatc form, that is for 

 the most part broader than long, but occasionally is some- 

 what more circular than usual. From its thinness it is a 

 little translucent, and is covered with a rather dull and 

 dirty yellow epidermidal coat, beneath which the shell 

 is of a whitish hue, and never banded nor variegated 

 with any other colour. The surface is almost smooth ; 

 numerous wrinkles of increase, and occasionally a few very 

 obscure spiral ridges may, however, be descried. Of the 

 three volutions which compose the shell, the two upper 

 scarcely occupy any appreciable portion of its area, being 



