RICE SHELLS. 43 



three strong, oblique folds which are very conspicuous. 

 The length of the shell is from an inch to two inches 

 or more. It is seldom found living, but dead and 

 broken shells are not unfrequently thrown up by the 

 waves. The folds on the columella, the dark brown 

 shell, and the black epidermis are decisive markings. 



The pretty little shell of Volvarina vaj-ia, Sby., 

 Vol-va-ri'-na va'ri-a, is about the size and shape of a 

 grain of wheat. It has a very short, rounded spire, a 

 long aperture and a plaited columella. Its surface is 

 very smooth and glossy, and varies in color from white 

 to brown, the shades being often laid on in bands and 

 stripes. It is a southern species and is found on rocks 

 between tides. 



There are several little pure white shells about the 

 size of a grain of rice, all of which are popularly 

 known as Rice Shells. Most of them live in the 

 warmer oceans, but one which here commonly passes 

 by that name is rather sparingly found on our coast. 



fits true name is Marginella Jewettii^ Cpr., 

 Mar-gin-el'-la Jew-ett'-i-i, a rather large 

 name for so small a shell. Fig. 23 gives 

 an enlarged view of the shell, with a little 

 Fig. 23. cross beside it to show the true length and 

 breadth. You will notice these little crosses beside 

 several other figures in the book. 



The shell is pure white, pear-shaped, and has no 

 visible spire. The columella is plaited, and. the aper- 

 ture extends the whole length of the shell, which 

 is rather less than one-fourth of an inch in length. 



Marginella subtrigoiia^ M. regtilaris and M. pyri- 

 fo7'ttiis are three species similar in form to the last, 

 but so very minute that they would hardly be noticed, 



