KEY-HOLE LIMPETS. 97 



stripes, running down from the small, oblong hole at 

 the top, suggest streams of red hot lava issuing from 

 the crater of a volcano. The coloring appears plain- 

 est on dead shells; the live ones are darker, smoother, 

 and less brilliant. 



Glyphis densiclathrata^ Rve., den-si-clath-ra^-ta, is 

 smaller, more delicate, and has closer and finer sculp- 

 turing. Length about half an inch, color white or 

 gray, hole circular; below tides. 



FissurellidcEa calliomarginata, Cpr. , Fis-su-rel-li- 

 de^-a cal-li-o-mar-gin-a'-ta, is a small, deep-water 

 species. Its shell is low-arched, with a large, oblong 

 hole, and roughened rays. The margin is crenulated 

 and the inside is white. 



FissMrellidcea bhnaculata, Dall, bi-mak-u-la^-ta, 



is the long name of the little shell shown in Fig. 82. 



^^^ Dead shells may frequently be found, and 



^^^g occasionally a live one may be gathered 



from the sea- weed or the rocks. The shell 



^^^■^^ is about one-fourth of an inch in length, 

 oblong, with rounded corners and external sculptur- 

 ing. The hole in the center is shaped like the shell. 

 The color is white, but there is a dark, triangular 

 spot on each side, which gives it the name bimacu- 

 lata^ meaning two-spotted. 



(7) 



