9 6 



KEY-HOLE LIMPETS. 



It has a huge yellow foot and a black mantle, which 

 nearly conceals the white shell which rests upon the 

 animal's back. 



This shell is marked by many radiating ribs, and 

 concentric lines of growth; it has a large, oblong 

 hole to one side of the center, around which, inter- 

 nally, is a thick rim of enamel. The crenulated or 

 scalloped edge of the shell is a marked feature, and 

 suggested the name. 



Internally, the shell is of a pure, glossy white, but 

 the outside is somewhat dingy. This mollusk is not 

 very abundant, and is seldom found alive near the 

 shore. 



Glyphis aspera, Bsch., Gly'-fis as'-pe-ra, Fig. 80, 



has a rough shell, more 

 sharply conical than the 

 last, with a small oval 

 hole at the top, quite 

 different from the nar- 

 row, oblong slit of the 

 next shell. This shell 

 has a wrinkled edge, a 

 Fi £- So - white interior, and a 



gray or striped outside. Its common length is an 

 inch and a half, though I once found a fine live spe- 

 cimen of twice that length. 



Fig. 81 represents the shell of our most common 

 Key-hole Limpet, Fissiirella volcano, Rve., Fis-su- 

 rel'-la vol-ca'-no. The dead shells 

 are abundant, and living speci- 

 mens, with yellow foot and red- 

 striped mantle, may often be found 

 on the rocks at low tide. 

 Flg ' 81 ' The shell is about an inch in 



length, and is oblong conical in form, while the red 



