MARSHAT.I, : ADDITIONS TO "BRITISH CONCHOLOGY." 30I 



water West (Span) ! Achil Island, Bundoran, and Killala ; a single 

 specimen from the Long Forties, off Aberdeenshire (Dawson) ! 



Var. minor Monts. =var. /////^^rr// Jeff, non Michaud = C ^zV^/<?/- 

 Risso. — Scilly Islands (Burkill and J.T.M.) ; Sutherlandshire, from 

 haddocks (Baillie)! Achil Island, Killala Bay, North Rona, 24f. I 

 have a white specimen from Scilly. This is a dwarf form of the type, 

 and not Midland's species. When found imperfect the two shells are 

 not easily separable, the differences being mainly embryonic ; but in 

 C. bicolor 'Rasso {iZ26)=C. philbeiti M.\ch. (1829) the shell is more 

 oblong, and the embryonic whorls are i|, coarse, and blunt; in C. 

 ptirpjirea and var. initior they are 3I, conical, and sharp. The var. 

 minor is figured by Forbes and Hanley as presumably C. philberti 

 Mich.,'^ but the apex shows that it is the minor form of C. purpurea. 

 It is unfortunate that the immature forms of the mollusca have not 

 been more studied. As I have pointed out in various instances in 

 the course of these papers, the embryonic whorls are often a sure 

 guide, sometimes, indeed, the sole criterion of determination, and in 

 almost all instances they are worthy of investigation. The Rev. R. 

 Boog Watson has already pointed out that " young shells are always 

 peculiarly instructive, though lamentably despised even in the best 

 Museums."^ 



Var. laviae Phil. == var. oblonga Jeff.— Not altogether confined to 

 the Channel Islands ; I can add the Scilly Isles (Burkill and J.T.M. ); 

 Lundy Island (coll. MacAndrew); Freshwater West (Tomlin); Jersey, 

 Penzance, and Bundoran. The sculpture varies in this variety, but it 

 is usually finer than in the type. My Jersey specimens are twice the 

 usual size, and similar to those from the adjacent coast of France. 

 Var. oblonga Jeff, is not separable from var. lavia Phil., and Philippi's 

 name was long prior to Jeffreys'. C. bicolor Risso is similar in size, 

 sculpture, and contour, but the apex is specifically different. 



Clathurella formosa Jeff.— May be considered a British species, 

 having been dredged by the ' Porcupine ' on the slopes of the English 

 Channel, and off the Shetlands in 345f.; also by the Scottish Fishery 

 Board about 50 miles off the Butt of Lewis in 545f, a single speci- 

 men only, and recorded as Pkurotomella packardi (Verrill).^ It was 

 also dredged by the ''J'riton' between the Hebrides and Faroes in 

 57of.* 



I have not seen the specimen cited above from the Butt of Lewis, 

 but there has been a lamentable confusion about this species on the 

 part of Gwyn Jeffreys, whose description differs from his figures, and 



1 Brit. Moll., vol. iv., pi. cxiii., fig. 4. 



2 Challenger Gastropoda, p. 246. 



3 Simpson : Notes on Rare Moll., Joiirn. Conch., 1910, vol. 13, p. 114. 



4 Jeffreys ; Moll. ' Triton ' Exp., Proc. Zool. Soc, 1882, p. 397, pi. 44, figs. 99a, ggb. 



