948 DIVISION III. ARTICULATED ANIMALS.—CLASS I. ANNELIDES. 
Some of these tubicoles live like solitary hermits, others love company ; 
for instance, the Sabella alveolaris, which often covers wide surfaces of 
rock near low-water mark with its aggregated tubes. When the flood 
recedes, nothing is seen but the closed orifices; but when covered with the 
rising waters, the sandy surface transforms itself into a beautiful picture. 
From each aperture stretches forth a neck ornamented with concentric rings 
of golden hair, and terminating in a head embellished with a tiara of deli- 
cately-feathered, rainbow-tinted tentacula. The whole looks like a earden- 
bed enamelled with gay flowers of elegant forms and variegated colors. 
The principal genera are SERPULA, SABELLA, TEREBELLA, AMPHITRITR, 
Syruostoma, and DENTALIUM. 
ORDER II. THE DORSIBRANCHIATA. 
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This order comprises those Annelides which have their gills distributed 
throughout the whole length of the body. It is divided into twenty-four 
genera. These are, for the most part, creatures of wonderful structure ; 
and as our space will not allow us to refer to them all, we will introduce 
two of the groups which, we think, will serve best to represent the whole. 
Genus Evunice.— These animals are furnished with tuft-like gills, and 
the trunk is strongly armed with three pairs of horny jaws, while each of 
their feet has two cirrhi and a bundle of bristles. 
With the idea of worms we generally connect the notion of incomplete- 
ness ; we are apt to consider them as beings equally uninteresting and ugly, 
and disdain to inquire into the wonders of their organization. But a cursory 
examination of the Hunice gigantea, a worm about two and a half feet 
jong, and frequently occurring on our coasts, would alone suftice to give us 
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a very different opinion of these despised, but far from despicable creatures. 
The whole body is divided into segments scarce a line and a half long, and 
ten or twelve lines broad, and thus consists of about three hundred rings, 
a brain, and three hundred ganglions, from which about three thousand 
nervous branches proceed, regulate the movements, sensations, and vegeta- 
tive functions of a Euntce. Two hundred and etghty stomachs digest its 
food; five hundred and fifty branchie refresh its blood; six hundred 
hearts distribute this vital fluid throughout the whole body, and thirty 
thousund muscles obey the will of the worm, and execute its snake-like 
movements. Surely an astonishing profusion of organs ! 
HAvirnea. — This animal has three leaflets in its branchix, between two 
of which is a very small crest: it has no jaws. ‘There is one species — 
aAlphiodita aculeata, Linn.—quite common, which is among the most beau- 
