1883.] ' lightning' AND ' POKCUPINE ' KXPEUITIONS. 109 



Perhaps that character and the operculum having a miiltispiral 

 nucleus on the underside may constitute sufficient grounds to sepa- 

 rate the present species from Turbo ; and in that case the genus 

 might be called Cantrainea in honour of the discoverer and cele- 

 brated conchologist. I have had an opportunity of examining and 

 comparing his species and its variety through the obhging attention 

 of M. Van den Broeck. 



1/Phastanella pulla, Linne. 



Turbo pullus, L. S. N. p. 1233. 



P. pulla, B. C. iii. p. 338, pi. viii. f. I ; v. p. 204, pi. Ixiv. f. 1. 



'Porcupine' Exp. 1870 : Atl. St. 8, 9, VigoB., 26, Tangier B., 

 Gibraltar. Young and dead shells, wliich were probably carried out 

 by tidal or other currents from the littoral and sublittoral zones 

 which this species usually inhabits. The greatest depth at which it 

 has been noticed as living is 15 fathoms. 



Distribution. From the Orkneys and Stornoway southwards to the 

 Morea, Black Sea and Adriatic, Mogador, coast of Barbary, Madeira, 

 Canaries, and Guadaloupe(ifea«<, fide Petit) ; 0-120 fms. Specimens 

 from the greater and perhaps any depth beyond 15 fathoms may 

 have been drifted. 



Fossil. Pliocene : Antibes and Italy. Post-tertiary : N. Ireland 

 and Nice. 



Turbo picfus of Da Costa and several other unnecessary synonyms. 

 Lamarck described it as Turbo pullus, and did not include it in his 

 genus Phasianella. I regard P. intermedia of Scacchi and P. tenuis 

 of Midland as varieties of this common and therefore variable species. 

 Very young specimens exhibit a small umbilical slit. 



Family IX. LittoriniDjE. 

 (/ 1. Lacuna crassior, Montagu. 



Turbo crassior, Mont. Test. Brit. p. 309, t. 20. f. 1. 



L. crassior, B. C. iii. p. 344 ; v. pi. Ixiv. f. 2. 



' Porcupine' Exp. 1869 : St. L. Foyle, 33. 



Distribution. Spitzbergen, White Sea, Russian Lapland, N. Pacifici 

 Greenland, G. St. Lawrence, British coasts, and Etretat ; 0-12 fms- 



Fossil. Post-tertiary : Belfast and Hull. 



L. glacialis, Moller, L. vestita, Metzgcr, and perhaps Turbo 

 pallidus, Donovan. 



The characteristic canal is frequently wanting both in young and 

 adult specimens of this species. Dr. Collingwood has always found 

 it living and feeding on the polyparies of Alcyonidium hirsutum. 



I, 2. Lacuna divaricata, Fabricius. 



Trochus divaricatus, Fabr. Fn. Grocnl. p. 392. 



L. divaricata, B. C. iii. p- 346, pi. viii. f. 2 ; v. p. 204, pi. Ixiv. f. 3. 



' Lightning ' Exp. St. 4, 5, 7. Drifted. 



'Porcupine' Exp. J869: Donegal B. 



Distribution. Arctic seas in both hemispheres, Iceland and Faroe 



