30 A CHANCE FOR STUDY. 



page, concerning the different kinds of Cerosto^na^ 

 apply equally well to this genus, and a careful study 

 of the variations seen in specimens which are found 

 in different localities and under different conditions is 

 highly interesting. 



Accurate observations by any one may prove valu- 

 able, both to the observer and to the cause of science 

 in general. There are many things yet to be learned 

 about even our most common animals, and no one 

 need despair of discovering some new truth. 



It is a good thing to know the names of the objects 

 which we are studying, for that enables us to speak of 

 them intelligently and definitely ; but to this knowl- 

 edge of the name we will trs^ to attach all available 

 facts which relate in any way to the nature and habits 

 of the creature that we are studying. 



Moiioceros higiibre^ Sowb., lu-gu^-bre, found on the 

 coast of Ivower California, and perhaps a little farther 

 north, has a thick, heavy shell about an inch long. 

 The wall of the aperture is of a brown color, and is 

 marked with several rows of white tubercles. The 

 little horn near the canal is very distinct. 



In olden times, the inhabitants of ancient Tyre 

 used to get a purple dye from the bodies of several 

 kinds of moUusks which lived along the shores of the 

 Mediterranean Sea. It is said that this dye can be 

 obtained by pressing upon the operculum, and that it 

 is of a light color at first, but turns darker by expo- 

 sure to the air. Large quantities of shells are found 

 near Tyre, which seem to have been broken in stone 

 mortars, doubtless for the purpose of obtaining this 

 precious purple dye. How successfully the coloring 

 fluid may be obtained from our own species remains to 

 be determined, but the ancient custom of extracting a 



