IV IXTEODrCTIOX. 



surly, snappish, peevish person called a crusty fellov\-; they will 

 now understand what is meant by a crustacean and crunfaceoJoq//, 

 that part of Zoolofjy which treats of crustaceous animals. They 

 constitute quite a large family, these olocjics, and have a stranjje 

 way of twisting themselves about, and exchanging limbs and 

 features, so that one is puzzled at times to tell which is which. 

 But here we have fixed two of them, called Testaceology and 

 Cri'staceology, twin brothers, and very much alike in their char- 

 acteristics. Lot us have a good look at them, so that we may 

 know them again if we should lose sight of them for awhile. 

 Now we will spell over the name of the first — 



CONCHOLOGY. 



"VMiv, it is changed already I Has this science of shells then 

 anotlier name? Yes, and this is it, pronounced konff-koUo-f/j/, and 

 derived from the Latin concha, which means properly a shell-fish 

 with two shells, joined by a hinge, as the oj'ster, the cockle, etc. 

 Tliis present volume then is a work on Cuncholoffi/, the subject 

 of it IS Conchiferom, and wlioever studies it will be doing some- 

 thing towards becoming a Cunchuloffi.st. 



So much for names and titles; but still we have the question 

 to answer, "What aiv shells? In a learned work called a Cydo- 

 pne.lia. we find it stated that "shell is the hard calcareous (that is 

 chalky) substance which protects, either partially or entirely, the 

 testaceous molhisks externally, or suj)ports certain of them inter- 

 nally." All this you will understand, except perha])s the word 

 'moilusks;' this is a term applied to soft-bodied animals, such as 

 shell-fish, snails, etc., about which we shall have more to say as 

 we proceed. By this we learn that all shells are not external or 

 outer coverings, some are internal or inner supports for the soft, 

 jelly-like bodies to which they belong, thus performing the duty 

 of bones. An example of this is seen in the shell of the Cuttle 

 Fish, called by naturalists Sepia, a description of which will be 

 found further on in the book. 



Shells are either CrystaUiue or Granular. !Xow look at those 

 two words, they almost explain their own meaning. Crystalline 

 shells are those which have more or less of clearness, transparency 

 as we say, so that if held against the light it shews through 

 them; they are sometimes called Porcellanous shells, from their 

 resemblance in this respect to porcelain, or chinaware; the Common 

 Cowry, (Cyprcea Tiffris,) is a shell of this description. 



Granular, or, as they are sometimes called, Concreiionary shells, 

 are the most hard and compact; it is in these that the substance 



