64 JOURNAL OF CONCHOLOGY, VOL. 9, NO. 2, APRIL, 1898. 



C. laevis Mtros.— Scilly Isles (Burkill and J.T.M.). 

 Var. navicula Jefifr. — Sutherlandshire (Baillie) ! 



C. marmoreus Fab. — Mr. Pearcey has taken specimens in the 

 Firth of Clyde 2^ inches in length. 



C. ruber, C. Icevis, and C. marmoreus are somewhat confusing in 

 colour and appearance, especially when not well preserved ; in the 

 latter case, the girdle may be found to afford the most distinguishing 

 character. That of C. ruber is finely granulated, and has a mealy 

 appearance ; that of C. Icevis is much broader, and under a lens 

 resembles hair-cloth; while that of C. marmoreus is equally broad 

 as the last, but smooth except under a high power. 



Patella Lister. — A very able paper on the limpet tribe has been 

 given by Mr. Dall, 1 and a highly interesting paper on the habits of 

 the limpet by Mr. Clark Hawkshaw. 2 



Dr. Lawrence Hamilton," in experiments on the adhesive power ot 

 the limpet, came to the conclusion "that while some portion of the ad- 

 hesive power may or may not be due to atmospheric pressure, a very 

 considerable amount, if not the major part, or perhaps all, is probably 

 dependent upon the throwing out of a very tenacious substance..'' 



As regards the " homing " of the limpet, I am of opinion that the 

 return of the animal to its starting-place is due to its scar having all 

 the inequalities correspondant to the irregularly serrated edge of its 

 shell, as these inequalities would add considerably to its mechanical 

 hold ; whereas it would be inconvenient, and not quite safe from 

 enemies, if it had to adhere to any surface haphazard each time it 

 travelled. 



Dr. Jeffreys has related how the lighthouse-keeper at Scalpa, in the 

 Hebrides, had noticed rats on the rocks feeding on the limpets, which 

 they detached " by a sudden jerk with their noses ; should the first 

 effort fail, another is never attempted against the same individual, now 

 warned and adhering closely to the rock ; but the rat instantly 

 proceeds to others off their guard, until enough food is procured." I 

 have noticed the same thing in some parts of Torbay, where rats 

 abound in the cavernous cliffs, and in quietly lunching after a 

 morning's work at low tide, I have often seen them at their work. 

 My attention was first attracted by one day seeing my little black-and- 

 tan terrier excitedly chasing something among the boulders at the 

 water's edge, until he succeeded in intercepting and keeping at bay an 

 unusually large and fierce rat, which he managed to dispose of after 

 several " rounds." Mr. Collings, the Seigneur of Sark, has several 



1 Exploration of Alaska, p. 118 et seqq. 



2 Journ. Linn. Soc. (Zool.), vol. 14, p. 406-411, iE 



3 Nattiral Science; Oct., 1892. 



