PATELLA. 425 



some other kind of food, possibly infusorial. When it 

 moves about, it makes upon the rock a curious fucoid-like 

 track of some breadth, probably caused by the edges of 

 the shell. On calcareous rocks, and especially on chalk, it 

 frequently, as it were, excavates a cavity for itself, appa- 

 rently by the action of the carbonic acid set free during 

 respiration, since the marks of the action of the ciliary 

 currents from the gills are distinctly visible. This animal is 

 sometimes used for food, though much too leathery to be- 

 come a delicacy. As bait it is very valuable to fishermen. 

 Dr. Johnston, in some very interesting notes on the Lim- 

 pets of the Berwickshire coast,* calculates that in Berwick 

 alone there is an annual consumption of no fewer than 

 11,880,000 Limpets for this purpose. "From constant war- 

 fare," he says, " the numbers have now greatly decreased ; 

 there is not now one out of ten that there were twenty 

 years ago, and the collecting of them has become tedious 

 enough." In the " Annals of Natural History" for June 

 1839, there is a very interesting paper by Mr. Patterson 

 on the use of the Limpet as food in the north of L-eland. 

 It is therein stated that the Limpet gatherers, thirty in 

 number, at Larne in Antrim, earned in one season of four 

 months, no less than one hundred pounds sterling. 



The Patella vulgata ranges along the Atlantic shores of 

 Europe. 



P. ATHLETICA, BcaU. 



Substance of the shell white ; ribs very numerous, narrow, 

 much elevated, armed with toothlike scales in a regular series, 

 interstices wholly or partially stained with rich brown ; inside 

 more or less of a whitish cast, spatula tinged with orange- 

 yellow. 



* Berwickshire Nat. Club Report for 1842. 



VOL. n. 3 I 



