SEE 



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H A 



slightly tortuous, composed of nu- 

 merous thin layers of shell contain- 

 ing much animal matter. In 

 structure, this fossil resembles the 

 Serpula compressa, but it does not 

 diminish so rapidly. "Width half 

 an inch. It is found near Ludlow 

 very abundantly, and generally 

 throughout the Upper Ludlow B-ock 

 of Salop, Hereford, Radnor, &e." 



SE'EEATE. | (serratus, Lat.) Jagged ; 



SE'EEATED. ) notched. 



1. In botany, applied to leaves, 

 the margins of which resemble a 

 saw, the teeth pointing towards 

 the extremity of the leaf. 



2. In entomology, applied to the 

 bodies of insects, the margins 

 having jagged incisions, like the 

 teeth of a saw. 



SE'EETJLATE. } (from serrula, a little 



SE'EEULATED. ) saw, Lat.) When 

 the edges of leaves or margins of 

 shells are very finely jagged or 

 notched, they are said to be ser- 

 rulated, and not serrated. 



SEETULA'EIA. A genus of aborescent 

 corals belonging to the family Tu- 

 bularii. 



SE'ETJM. (serum, Lat. serum, Fr.) 

 The thin, watery, transparent part 

 of the blood. 



SE'SAHOID. (from <rc<rap/, an Indian 

 grain, and etov, resemblance, Gr. 

 sesamoide, Fr.) The name of some 

 exceedingly small bones found at 

 the root of the thumb or great-toe. 

 It is the opinion of some naturalists 

 that sesamoid bones are rather to 

 be regarded as depositions of bony 

 matter, in parts disposed to its 

 reception, as ligament, cartilage, 

 &c., than as intrinsic portions of 

 the skeleton ; they are larger and 

 more numerous in the hands and 

 feet of such as take laborious 

 exercise. 



SE'SQTJI. (A contraction of semisque, 

 Lat. signifying and a half.) A 

 prefix to many words signifying 

 the quantity and a half more. A 

 sesqui-oxide is therefore a combi- 



nation with one equivalent and a 

 half of oxygen. 

 SE'SSILE. (from sessilis, seated, Lat.) 



1. In botany, applied to flowers 

 when placed directly on the branch 

 or stem ; also to leaves when they 

 grow directly from the stem, 

 branch or root, without any foot- 

 stalk : any part of a plant which 

 commonly is borne on a stalk, is 

 said to be sessile when it has no 

 stalk. 



2. Applied to animals. No truly 

 sessile animal is provided with sight. 



SE'VEEITE. An earthy mineral con- 

 sisting of alumina, silica, and 

 water. It is found in small mas- 

 ses, white, without lustre, and 

 slightly translucent. It was dis- 

 covered near St. Sever, in Prance, 

 whence its name. 



SETA'CEOUS. (from seta, a bristle, 

 Lat.) Bristle-shaped; bristly. 



SHALE, (schale. Germ. Schiefer Thon 

 of Werner : argile schisteuse of 

 Brochant.) Shale occurs masive 

 only; its usual colour is grey, 

 sometimes blueish, blackish or yel- 

 lowish. Often easily cut by the 

 knife. Specific gravity about 2-64. 

 Adheres to the tongue, yields an 

 argillaceous odour when breathed 

 upon, absorbs water considerably, 

 and often falls gradually to pieces 

 in that liquid, but never forms a 

 paste. Slate z clay ; indurated slaty 

 clay. 



Fracture slaty, sometimes nearly 

 earthy, and is dull unless it con- 

 tains casually imbedded mica, 

 which renders it glimmering. It 

 is fusible before the blow-pipe. It 

 is found resting upon, as well as 

 interposed between, beds of coal, 

 which it invariably accompanies. 

 Some shales are highly bituminous 

 and burn with a bright flame. 

 Shales frequently contain impres- 

 sions of fishes, reeds, and ferns. 



SHA'NKLIN-SAND. (The Glauconie 

 Sableuse of the French geologists.) 

 Called also the lower green sand. 



