LIMPETS. lOI 



been removed from the shell, observe the horse- shoe 

 shaped muscle scar. 



One of the most common of the limpets is named 

 AcmcEa patina, Esch., x\k-me'-a pat'-i-na. Fig. 88 



shows the form. It is oval, 

 flattened, with a nearly cen- 

 tral apex ; from this radiate 

 fine lines or striae, sometimes 

 Fig 88. quite indistinct. The outside 



is of a dark color; internally there is first a dark ring 

 around the edge, then a broad, bluish- white lining, 

 and a patch of brown near the center. The details 

 of the coloring vary greatly, and some young speci- 

 mens are very prettily checked with green and brown. 

 The common length of the shell is from an inch to 

 two inches. Mr. Dall considers this species as iden- 

 tical with the common Acmcea testiidinalis, Fb. and 

 Han., which abounds on both sides of the North 

 Atlantic. 



AcmcEa scab7'a,^\\.\X., ska'-bra, resembles the last 

 species in general form, and I once thought it was 

 only a variety. But an examination of many speci- 

 mens has shown me that the head and mantle of this 

 species are of a dark color, while in patma they are 

 always white. 



The shell is low-arched, and is covered with scaly, 

 radiating ridges, which give it the appearance and 

 feeling of a fine-cut file. It is usually whitish or 

 light-brown in color, though sometimes it is darker. 

 The average length is one inch. I have seen a few 

 ver}^ large and thick shells, which had belonged to 

 aged specimens, and which proved their identity 

 only by their white color. 



