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POBCELAIN CRAB 312 POBOSITY quantities of porcelain are produced in the United States. Trenton, N. J., is a center for the manufacture. See Pot- tery. PORCELAIN CRAB {Porcellana) , a name for certain Crustacea, typical of the family Porcellanidx, small smooth crabs. So called from their smooth pol- ished shell. PORCELLANITE, a very hard, im- pure, jaspideous rock, frequently met with in the immediate vicinity of in- trusive eruptive masses. In most cases porcellanite is simply a highly baked and altered argillaceous rock — shales being frequently converted into porcellanite along their line of junction with an igneous rock. PORCH, a covered entrance to a building; a covered approach or vesti- bule to a doorway. When a row of columns is added it becomes a portico. In some old churches the porches are of two stories, the upper being termed a parvis. POBCH, THE, the School of the Stoics, so called because Zeno, the philosopher and founder of the sect, gave his lectures in the Athenian picture-gallery, called the stoa poikile, or painted porch. POBCTJPINE, the popular name for any individual of the genus Hystrix or the family Hystricidse (divided into two groups, Hystricina and Synetherina, or two sub-families, HystriciTise and Sphin- ffurinse). The common porcupine {H, PORCUPINE cristata) may be taken as a type of the true porcupine. It is found in the S. of Europe, and the N. and W. of Africa, is about 28 inches long, exclusive of the tail, about four inches. It is somewhat heavily built, with obtuse head and short limbs. The head, fore quarters, and under surface are clothed with short spines, intermixed with hairs, crest on head and neck, hind quarters covered with long sharp spines, ringed with black and white, and erectile at will. They are but loosely attached to the skin and readily fall out. It is a purely vege- table feeder, and lives in holes in the rock, and burrows in the ground. The hairy-nosed porcupine is H. leucura (or hirsutirostris) from Syria, Asia Minor, and India; and the brush-tailed porcu- pines belong to the genus Atherura. Tney have long tails, tipped with pecu- liar flattened spines. POBCTJPINE CBAB, Lithodes hystrix, a native of Japan. The carapace is tri- angular, and, like the limbs, thickly covered with spines. It is dull and slug- gish in its movements. POBCUPINE FISH (Diodon hystrix), a fish of the order Plectognathi, found in the tropical seas. It is about 14 inches long, and is covered with spines or prickles. POBCUPINE GBASS (Triodia or Festuca irritans) , a brittle Australian grass which it is proposed to utilize in the manufacture of paper. See Spini- FEX. POBCUPINE WOOD, the outer por- tion of the trunk of the cocoanut palm, a hard, durable wood, which, when cut horizontally, shows beautiful markings, resembling those of porcupine quills, POEGY, POGGY, or PAUGIE, Pagrus argyrops, an important food fish found on the coast of the United States. It attains a length of 18 inches and a weight of about four pounds. POBIFEBA ("pore-bearing"), a term occasionally employed to designate the sponges. POBK, the flesh of swine; one of the most important and widely used species of animal food. The swine was forbid- den to be eaten by the Mosaic law, and is regarded by the Jews as especially typical of the unclean animals. Other Eastern nations had similar opinions as to the use of pork. Pork contains less fibrine, albuminous and gelatinous mat- ter than beef or mutton, and is indigest- ible to anyone who is weak and debili- tated. In the form of bacon, however, when well smoked and carefully pre- pared for the table, it acts as a stimulant to the stomach and is e5^pecially relished for breakfast. In the United States, prominently in the West, the pork-pack- ing industry is one of the greatest factors of wealth. POROSITY, the quality or state of being porous or of having pores; porous- ness; specifically, that property of mat- ter in consequence of which its particles are not in absolute contact, but are sepa- rated by pores or intervals; the opposite to density.