310 LITTORINID^. 



of the whorls ; aperture nearly circular, the lip hevelled withhi to a 

 sharp edge ; the pillar margin broadly flattened and white, contin- 

 uous with the outer lip ; color of the interior correspond- 

 Fig. 578. -j^g ^Q ^Y\e exterior color ; operculum horny, semi-heart- 

 shaped, smooth, sub-spiral. Length, eight tenths of an 

 inch ; breadth, nine tenths of an inch ; divergence, eighty- 

 five degrees. 



. ra la a. Pq^jj^jJ aloug tlic wliolc coast. Their resorts are usually 

 exposed to the open sea. They are found on rocky shores in great 

 abundance, and at low tide are easily obtained from the rocks and 

 rock-weed, to which they cling, and on which they are seen in rapid 

 motion. 



The animal has the head orange, darker aliove, and the foot of a 

 dral) or cream color. 



The varieties of coloring are innumeraljle ; comliining the colors 

 al)ove-mentioned in every possible manner. They consist princi- 

 pally, however, in bands of different widths, from hair lines, up to 

 a third of the width of the l)ody whorl ; but the surface is sometimes 

 reticulated, or marked with triangular spots. 



The great points of distinction are the smooth surface, short, 

 depressed spire, broadly flattened i)illar, and, above all, the orange- 

 colored head of the animal. 



Its proportions vary with its age. While young the aperture is 

 not much longer than the spire, but at maturity it is seven eighths 

 of the length of the shell. 



This shell would by many be considered the same as the Turbo 

 neritoides of authors. It may be the T. ncrituides of Linna3us, but 

 not of F(^russac and Lamarck. I have sent our shells to Mr. Sow- 

 erby and Dr. Loven, who are of the opinion that they are distinct. 

 To some of the small European specimens parallels might be pro- 

 duced from our largest ones ; but in general the spire of our shell 

 is less depressed, has no decided angle bounding the flattened spire, 

 and it is less narrowed forwards. Mr. Sowerby sent a shell labelled 

 Liu. cxpansa, Brown, from the Frith of Forth, which much more 

 closely resembles our shell. Dr. Loven has given to a dirty olive- 

 colored shell from the coast of Norway the name of L. sqvalida; 

 but it is precisely the same as similarly colored shells of this spe- 

 cies. As there is still so much cause for doul)t, it seems better, for 

 the present at least, to retain Mr. Say's specific name. 



Halifax to Labrador (^Willis) ; Beauport, fossil {Daicson). 



