LITTORINA LITTOREA. 649 



however, to the sulcafxi group. It has been reported recently by Mr. J. T. 

 Marshall, from Aberdeenshire, as " not unconnnon." 



Var. sulcata, S. Woodward. Plate LII, tigs. 14, 15. 



1833. Turbo siilcafiis, S. Woodward, Geol. of Norfolk, p. 44, pi. iii, figs. 14, 15. 



1848. Litiorina liitorea, var. sulcata, S. V. Wood, Mou. Crag Moll., pt. i, pi. x, fig. l-ib. 



1864. Littorina liforea, var. sulcata, S. P. Woodward, iu White's Hist, of Norfolk, ed. 3, p. 118. 



Dimensions. — L. 28 mm. B. 15 mm. 



Distribution. — Not recorded livinof. 



Fossil : Icenian Crag : Bramerton, Thorpe. 



Remarks. — One of the specimens of the shell here figured was found at Bramerton 

 by the late T. G. Wigham ; it very nearly corresponds to Wood's varietal type 

 (fig. 14<b); the other is larger with a broader base. Both agree also with that one 

 originally described by S. Woodward as Turbo snlcatus. His son, Dr. S. P. 

 Woodward, considered, as did Wood, that it should be regarded as a variety of 

 L. littorea. 



Var. distorta, nov. Plate LII, fig. 16. 



1872. Littorina r^cdis (distorted), S. V. Wood, Mou. Crag Moll., 1st Suppl., pt. i, p. 79, pi. v, fig. 10. 



Distribution. — Recent : Southend (Jeffreys). 



Fossil : Icenian Crag : Bramerton and elsewhere. 



Remarks. — This form differs from the variety deformis of Wood, the latter being 

 probably, as suggested below, a variety of his var. elegans. The malformation of 

 the present specimen seems to have been due to a fracture of the shell at an early 

 stage in the life of the animal and a subsequent regrowth at a different angle. In 

 Wood's opinion such irregularities may have been caused by variation in the condi- 

 tions under which these molluscs lived, and by a different amount of salinity due 

 to the daily ebb and flow of the tides, or a variable temperature of the water. 

 Jeffreys states that at one part of the Thames, at Southend, he found most of the 

 specimens of Littorina more or less eroded and in some cases distorted. This 

 would hardly explain, however, the extraordinary difference in form and sculpture 

 of the various fossils which our best Crag authorities have grouped as varieties of 

 the recent L. littorea. In his 1st Supplement {loc. cit.) Wood expresses the opinion 

 that some of these distorted shells may belong to L. rudis. 



Var. conica, nov. Plate LII, fig. 17. 



Varietal Characters. — Shell conical, trochiforni ; whorls flattened ; ornamented 

 by fine spiral lines which extend to the base, and by a strong rib above the suture 



