INTRODUCTION. XI 



surface, form a fruitful soil for the nourishment of vegetation. 

 The character of the testaceous deposits, too, enable geologists, as 

 those who study the nature aud structure of the earth are termed, 

 to come to important conclusions on many points connected with 

 the subject of this iuvestigation. And if we include, as the subject 

 of our book allows, the inhabitants of shells, how wide a field of 

 usefulness opens before us. How many thousands of our industrious 

 population depend wholly, or in part, upon the capture and sale 

 of shell-fish for their support. In some parts, as the western 

 and northern Islands of Scotland, they have in times of scarcity 

 afforded sustenance to the dwellers on the bleak and barren shores, 

 who but for them must have perished. But of all this w^e shall 

 have more to say when we come to describe the different members 

 of the testaceous family. We will now offer a few remarks upon 



THE INHABITANTS OF SHELLS; 



Which belonging to that division of Natural History called the 

 Mollusca, from the Latin Mollis — soft; these Mollicscoas animals, 

 then, are animals having a soft body, aud no internal skeleton. 

 You may be quite sure that a Mollitsk will never break its bones, 

 because it has none to break; it has a shell, however, which may 

 be broken, at least in some cases, for all Mollusks have not snug 

 habitations of the kind; bvit wander about the watery or earthy 

 world in which they live, quite naked; such as the sea and land 

 slugs, aud some worms, leeches, etc.: but with these w-e have 

 nothing to do, our present subject including only a part of 



MALACOLOGY, 



another member of that queer ology family, deriving its name 

 from two G-reek words signifying soft, and a discourse; hence it 

 means a discourse upon soft, or soft-bodied, auimals, that is mollusca. 

 It is only a part then of Malacolofjy that w^e have to do with; 

 that part which relates to the shell-inhabiting mollusks, and strange 

 creatures enough some of these are. We will have a look at 

 them presently; just now it will be sufficient to observe that the 

 moUivsca testacea, or soft-bodied animals, furnished with shells, 

 possess the power of exuding, that is, discharging from various 

 parts of their bodies a sticky kind of fluid, which mixing with 

 the chalky matter collected from the water, and becoming hard, 

 forms, in process of time, the shelly covering which is at once a 

 dwelHng and a defence for the inhabitant. 



Miss Pratt, in her delightful book on "Common Things of the 

 Sea Coast," observes of these shells that, "We gather up those 

 which we find, and looking at their structure woidd fain know 



