34 



DR JOHNSTON S DESCRIPTIVE CATALOGUE OF THE 



27. LoTTiA. Gray. 



Shell patelliform, generally depressed, witli the vertex inclined to 

 the anterior margin, and sometimes nearly marginal: muscular im- 

 pression non-symmetrical, being rather wider on the right side near 

 the head than on the left : internal central disk generally of a dark or 

 varied colour. The branchial plume is contained in a cavity over the 

 neck of the animal, and is only occasionally protruded. — See Sowerhy's 

 Genera of Rec. and Fossil Shells. 



1. X. virginea, shell oval, with the apex towards the anterior side, 

 greyish or pale-flesh colour, rayed with lines of a deeper red, even, 

 very obscurely striated ; the margin smooth, coloured and spot- 

 ted ; interior white or tinted with red. Diam. 5 or 6 lines. 

 Patella virginea. Mull, Zool. Dan. i. p. 13. tab. 12. fig. 4. 5. 

 Dilhu. Rec. Sh. 1052. Flem. Brit. Anim. 287. Lottia virgi- 

 nea, Aldevy in Ann. and Mag. Nat, Hist. viii. p. 403. 



Hah. Near low-water mark under stones, and in the roots of Laminaria 

 digitata, not uncommon. 



Head towards the narrow end of the shell. Tentacula white, awl-shaped ; 

 foot oval, with a plain margin, white ; cloak with a filamentous fringe 

 all round and about half a line within the margin, the filaments short, 

 equal, obtuse and white, while the margin itself is plain and marked 

 with purplish bands corresponding to those on the shell. The fila- 

 ments do not point outwards like the marginal filaments of the cloak 

 of Patella vulgata, but are all directed inwards and towards the body, 

 so that they are apparently more analogous to the branchial circle 

 than to tentacular filaments. The tongue is very long and ribbon- shaped, 

 rough, with the spinous teeth arranged quincuncially in five series, 

 and those in the middle series are much larger than those of the sides. 



In opposition to an opinion which I gave in the Magazine of Zoology and 

 Botany, vol. ii. p. 365, Mr Alder has very satisfactorily proved that 

 this pretty limpet is a Lottia, and to him we are indebted for an ex- 

 cellent description of the branchial organ. I am not, however, equally 

 convinced that our species is the Patella virginea of Muller, although, 

 in deference to Mr Alder's authority, I have here also followed him ; 

 for on examining Muller's excellent figures, I can see no trace of a 

 ciliated fringe anywhere ; which, on the contrary, is shewn, just as it 

 has appeared to me, in the figure 6 of Patella tessulata. 



" In tracing this species through all its stages, I find that in its very young 

 state, the red markings of the shell are not in regular lines, but have 

 a tessellated or chained appearance, exactly similar to those of Mr 

 Forbes's Lottia pulchella ; in fact, I cannot perceive any diflference 

 between my shells and specimens of Lottia pnlchella, kindly presented 

 to me by Mr Forbes." — J, Alder. 



