44 THE ECONOMIC ilOLLUSCA OF ACADIA. 



coast of New England prior to 1868, but has since spread 

 southward very rapidly, reaching Casco Bay about 1873, Cape- 

 Cod in 1875, New Haven, Conn., in 1879. The evidence 

 bearing upon the question of whether or not it is introduced, 

 would be out i)f place here. It will be found in the work by 

 the author, cited below]. 



Habits. It is not difficult to distingulish this shell from our other 

 littoral rock-loving Gasteropods. Our native Periwinkle, L. paUiatar 

 resembles it most closely; but that is much smaller, much thinner and 

 lighter and entirely lacks any of the revolving raised lines so well 

 marked in L. litorca. This latter character marks it 

 off well from young specimens of Lnnatia Juros. 

 From L. rudis it is separated by its greater size and, 

 the greater number and less prominence of its re- 

 volving lines and by the shape of its mouth or 

 aperture; in L rudis the latter is nearly round, in L. 

 litorea it is pear-shaped. From Purpura lapUlus and 

 Fig. 9. — Liltorbia Bucci uuni undatum il {& readily distinguished by the 

 litorea. Natural absence of a posterior prolongation of the shell into 

 Size. a canal Large spt-cimeiis are over an inch in length, 



but ihe average size is a little below this. 



The Periwinkle lives oa the rocks between tides. It is a vegetable 

 eater, and u.ses its long tile-like tongue or lingual ribbon, which its- 

 relatives employ to bore through the shells of other Molluscs, for rasp- 

 ing up minute sea weeds from the rocks. It really grazes on Ihese sub- 

 marine pastures as do cattle on land. This mode of taking its food 

 results in direct value toman, for in England Oyster cultivators distribute 

 them over the beds to keep the Oysters free from seaweed. It has not 

 been observed to attack other Molluscs. From its living on rock.s- 

 between tides and possessing considerable vitality, it is liable to be taken, 

 on ships with ballast, and it was probably in this way that it was intro- 

 duced into America from Europe. 



Economics. This is one of the best of our Food-molluscs, 

 a fact proven by the quantities sold both in foreign markets 

 and our own. It is not nsed as yet to any extent in the 

 United States, probably because it is of so recent introduction 

 and because of its scarcity in the vicinity of the markets of 

 New York — the great mollusc-market of the Eastern United 

 States. In England there are no exact statistics to show the 

 extent of its use, but it is estimated that in London alone 

 more than twenty-five hundred tons, worth fifteen thousand 



