PSI 



538 



PT E 



PtZLLIs'xfS, from \J/EAX^O>, U>>tuiiili:ri 



in speech. A defect of speech, in which 

 articulation is depraved. 



PSKUUEPIG'RAPHY, ^/u>dr,z, false, and 

 iTiyectpri, inscription. The ascription of 

 false names of authors to works. 



PSEU'DO. Ysr/dos. False : a prefix sig- 

 nifying false, counterfeit, or spurious. 



PSEUDUBLKP'SIS, from ^iiibrs, false, and 

 ^A6-J/;j, sight. False or depraved vision : 

 imaginary objects floating before the 

 sight, or real objects appearing with 

 imaginary qualities. 



PSEUDODIP'TERAL, ;}/,; and S;?,twice, 

 and trrtgov, wing. In architecture, in a 

 building, when the distance from each 

 side of the cell to the columns on the 

 flanks is equal totwointercolumniations. 



PSEUDO-ER'YTHINE. A substance of a 

 snow-white appearance, has the form of 

 scales or flat needles, is a little soluble in 

 water, but dissolves freely in alcohol. It 

 is obtained by digesting parmelia roc- 

 cellain boiling alcohol, and treating the 

 alcoholic solution exactly as if it were 

 intended to prepare erythine. It yields 

 no bitter principle. 



PSEUDO-METAL'LIC. An epithet for that 

 degree of lustre in minerals where it can 

 only be observed when the mineral is 

 held towards the light. 



PSEUDOMOR'PHOUS. Not having the 

 true or natural form ([Me$y, form), but 

 having a form arising from some acci- 

 dental circumstance. 



PSEUDO-SCOR'PIONES. A family of Arach- 

 nides, of the order Trachearite. The ge- 

 nera are Galeodes, Oliv., and Chelifer, 

 Geof. They take their name from their 

 scorpion-shape. They are all terres- 

 trial, and have an oval body with eight 

 legs. 



PsEUDo'THYRON,4*Eu5;S; and 0yg, door. 

 In architecture, a false door. 



PSECDO-TI'XEA. All the caterpillars 

 whose habitations (sheaths) are fixed or 

 immoveable, are termed Pseudo-tinea by 

 Keaumur; those which construct port- 

 able ones, which they transport with 

 them, are true tineae. 



PSIT'TACCS. The Parrot. A genus of 

 birds : order Scansoriee : name borrowed 

 from the Greek ^ITTO.XO^. The species 

 are well known for the facility with 

 which they learn to imitate the human 

 voice. They feed on all sorts of fruit, 

 climb among the branches of trees by aid 

 of their beak and claws, and build in 

 hollows of trees. Their voice is naturally 

 harsh and disagreeable, and they are 

 almost universally ornamented with the 

 brightest colours. They exist in both 

 continents, but hardly any of them are 

 found beyond the torrid zone. The species 

 are exceedingly numerous. 



I'so'vi:. "*'oa<. 1. The loins. 2. The 



name of two pair of musr-ies in the loins. 



PSORA'LEA. An extensive genus of 

 plants, many of them trees and shrubs. 

 Uiadclphia Drcandria. Nairn- from 

 V^o/eaj-, scabby, because the calyx and 

 other parts of the plant are more or Irss 

 besprinkled with glandular dots, causing 

 a scurfy roughness. Warm and temper- 

 ate climates. 



PSO&I'ASIS, from "^ca^oi, itch. A dis- 

 ease characterised by a rough scaly state 

 of the cuticle, sometimes continuous, 

 sometimes in separate patches, and for 

 the most part accompanied with rhagades 

 or fissures of the skin. Dr. AVillan de- 

 scribes eight varieties of the disease. 



PSYCHOL'OGY, from ij/vgt;, the soul, and 

 \oytg, a discourse. The doctrine of the 

 soul or mind: mental philosophy. 



PSY'CHOMANCY, from \^oj, and yuit.v- 

 ruot, prophecy. Divination by the dead, 

 in which they were supposed to appear 

 as spirits. 



PSYCHKOM'ETER, from 4/ti%os, cool, and 

 /*STOX, measure. An instrument for 

 measuring the tension of the aqueous 

 vapour in the atmosphere. 



PTAR'MIGAN. The white game, Tctra* 

 albus, Gm. See LAGOPUS. 



PTE'RIS. Brake. A genus of ferns. 

 Name from trT6ox, a wing, on account of 

 the resemblance of the loaves to winss. 

 There are 21 species, of which the com- 

 mon brake and stone-fern are the British 

 types. 



PTEROCAR'PUS. A genus of trees. Dia- 

 delphia Decandria. Name from trnfef, 

 a wing, and xae-ro;, fruit; in alMision 

 to the wing-like expansion of the legume. 

 Hot climates. The trees which afford 

 the red sandal-wood, the Andaman red 

 wood, one of the sorts of dragon's blood, 

 and the African kino, are species. 



PTERODAC'TYLI-S, \ An extinct genus 



PTERODAC'TYI E. ) of winged saurian, 

 placed among the Agamians, in the family 

 Iguanida, by Cuvier. It is only to be 

 found among the fossils of the old Jura 

 limestone. Name from jrre^ov, a wing, 

 and JaxrvAes, a finger ; its chief charac- 

 teristic being an excessive elongation of 

 the second toe of the fore-foot, which 

 was more than double the length of the 

 trunk, and most probably served to sup- 

 port some membrane, which enabled the 

 animal to fly, like that upheld by the 

 ribs of the dragon. 



PTER'IIMYS. The flying squirrel. A 

 genus of mammiferous animals ; order 

 Rodentia. Name from m^n, a wing, 

 and u,-j;, a rat. The skin of the flank 

 extending between the fore and hind left, 

 imparts the faculty of supporting tbeo- 



