37 G LITTORINID/H. 



give credit to retail dealers to the amount of from £60 to 

 £60 a week during the season. L. litorea may be always 

 known from L. rudis or any of its varieties in every 

 state of growth by being at least twice the size, having 

 flatter whorls, a much slighter suture, a more elongated 

 and sharj^ly pointed spire, and a straight outer lip. The 

 two species are frequently found together. 



It is the Turbo littoralis of Baster, Castanea tosta or 

 " marron roti '' of D^'Argenville, L. vulgaris of Sowerby 

 and Reeve, and L. communis of Thompson. 



The following two species of Littorina have been 

 erroneously introduced into the list of British mollusca : 

 both are West-Indian. 



1. L. ziczak (Trochus ziczak, Chemnitz), said to 

 have been found by Miss Hutchings in Bantry Bay. 

 I agree with Mr. Alder in assigning the supposed small 

 variety of this species, without the dark zigzag lines, 

 which was found by Lady AVilson near Sunderland, 

 and mentioned by Maton and Rackett, to L. neritoides. 



2. L. dispar {Turbo dispar, Montagu). "Poole'"' 

 (Rev. Mr. Bingley) ; " Portmarnock and Teignmouth '' 

 (Turton). 



Inest in explicatione Naturre insatiabilis qu^dain e cognoscendis 

 rebus voluptas, in qua una, confectis rebus necessariis, vacui negotiis, 

 honeste ac liberaliter possumus vivere. — Cicero deFinibus, Lib. IV. c. 5. 



EREATA. 



Page 254, line 6 from top, for " ancyloide," read *' ancyloides." 

 „ 258, line 9 from top, for " T. Noachina,'' read " P. Noackina." 

 „ 312, line 16 from bottom, for " T, cBgyjptiaca^'' read '• Monodonta 

 (sgyptiaca." 



