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"tbey formed a part, and whose form, structure, aud habit8> 

 have leaded to impress upon them the variety which they 

 present, or to those fossil remains which unite the living 

 world with the earliest records of creation, among which, 

 from the endurance of their materials and the stability of 

 their forms, shells are the most abundant and the most 

 perfect, and as ihe fossil shells are, in a very large propor- 

 tion, extinct species of living genera, they form one con- 

 tinuous series, aud are now so treated by naturalists. The 

 animals to which ttiese shells belong are the molluscs, 

 which constitute one of the four sub-kingdoms of the ani- 

 mal kingdom of natural history, placed by Professor Owen 

 the third in the scale according to their organization. They 

 are called the molluscs, or soft-bodied animals, because they 

 are altogether soft and pulpy, without any hard or bony 

 structure whatsoever, in contradistinction, (1st) to the Ver- 

 tebrata, or vertebrated animals ; —those namely which are 

 constructed with an internal vertebrated or jointed skeleton, 

 such as men, geese, rattlesnakes and whitings, for although 

 there is some dissimilarity in these four classes, which these 

 animxls typify, tbey all agree in the essential structure of a 

 vertebrated backbone, which brings thura all into one cate- 

 gory. (2nd.) To the Articulata, or articulated animals, con- 

 structed with a sort of external skeleton, articulated or 

 jointed, such as the Crustaceans, (Crabs and Lobsters for 

 example,) which need only be named to explain at once 

 what is meant by an articulated animal ; Spiders, which 

 form a class by themselves ; Insects, Worms and Barnacles 

 — in all of which this structure is to be traced, although 

 sometimes obscurely. These constitute the 1st and 2nd sub- 

 kingdoms ; the 4th is that of the Radiata or, radiated ani- 

 mals, so called, because their parts aud organs radiate from 

 a centre, of which the star-fishes are the type. The radiata 

 include the Zoophytes, Polyps, and others of the lowest 

 animal organizations, and the Infusoria, — microscopic Ani- 

 malculee, which swarm in the sea, and which are more par- 

 ticularly mentioned, because they contribute much to the 



