R H I 



Thefe arc fuppofed by fome to be of Roman origin, but 

 oilicrs conceive that they mark, the icite of a Saxon fort, 

 conftru&ed by the Mercians to defend their line of demar- 

 cation, as fixed by the great Ofia. This laft opinion is 

 rendered the more probable, bv the fact of there being fome 

 veltiges of a limilar fort more to the northward, and on the 

 fame line. Philip Yorke, efq., anceilor to the prefent pro- 

 prietor of ErJdig, was author of " The Hiitory of the 

 five royal Tribes of Wales,;" a work abounding with fo 

 much information, that it is greatly to be lamented that he 

 did not favour the world with his intended Stemmata, or 

 Fifteen Tribes. 



The diltridt in the vicinity of Rhiw-Abon, particularly 

 towards Wrexham, abounds with valuable mines. The 

 iron ore, found in the adjacent mountains, is exceedingly 

 rich, and affords excellent iron. The principal works 

 carried on are thofe of Brymba and Beriham. The latter, 

 which are fituated at Pont-y-Penca, confift of forges, 

 flitting, rolling, and (tamping mills, &c. with an extenftve 

 cannon foundery, inferior only to that on the banks of the 

 Carron, in North Britain. Befides cannon, thefe works 

 produce wheels, cogs, bars, pipes, cylinders, rollers, co- 

 lumns, piftons, &c. ; alfo furnace boilers, (team caillons, 

 and various other articles which were formerly made of 

 copper. Carlifle's Topographical Dictionary of Wales, 

 4to. 1813. A Tour round North Wales, by the Rev. 

 W. Bingley, B.A., F.L.S., 8vo. 2 vols. 1800. 



RHIZAGRA, in Surgery, an inllrument lor extracting 

 the ltumps of the teeth. 



RHIZANA, in Ancient Geography, a town placed by 

 Ptolemy in the interior of Dalmatia. — Alfo, a town of Alia, 

 in Gedrolia, upon the fea-coaft near Coiamba. Ptol. — Alfo, 

 a town placed by Ptolemy in Arachofia, between Alex- 

 andria and Arbaca. 



RHIZINIUM, or Riiimm'M, or Rhifon, a town of 

 Dalmatia, on a gulf to which it gave the name of Rhifo- 

 nicus Sinus. Ptol. 



RHIZIUM, Riiizf, a town of Aha, in the Colchide, 

 on the coalt of the Euxine fea, and W. of the mouth of 

 the fmall river " Rhizius." 



RHIZOBOLUS, in Botany, a name of Gartner's, 

 from p£a, a root, and ficAXu, to throiv, or caji, becaufe the 

 plant is remarkable for throwing out a number of roots. 

 — Schreb. 369. Mart. Mill. Diet, v. 4. Gaertn. t. 98. 

 (Caryocar ; I, inn. Mant. 154. Willd. Sp. PI. v. 2. 1243. 

 Pekea ; Aublet. Guian. v. 1. 594. .luff. 249. Lamarck 

 lllultr. t. 486.) — Clafs and order, Polyandria Tetragynia. 

 Nat. Ord. Sapindi, .Tuff. 



Gen. Ch. (.'<//. Perianth inferior, of one leaf, flediy, 

 cloven halfway down into live, roundilli, concave fegments. 

 Cor. Petals live, ovate, rounded, concave, llelhv, inferlcd 

 below tlie fegment oi the calyx, and nnicli larger. Stain. 

 Filaments very numerous, thread-fliaped, longer than the 

 corolla, inferted into the receptacle; anthers roundrfh. 

 Pi/l. Germen fuperior, fquare, in the bottom of the calyx ; 

 (tyles four, thread-fhaped, longer than the corolla ; ftigm; 

 obtufc. Pn'ic. Drupas four, kidney-fliaped, compreffed, 

 inferted by their wcdge-lhaped inner edge into the conical 

 receptacle, of cine cell, with a flediy covering, and a foft 

 pulp like butter. Seed. Nuts folitary, kidnev-lliaped ; 

 kernel', folitary, kidney-fhaped. 



Eff. Ch. Calyx five-deft half way down. Petals live. 

 Germen four- fuied, fuperior. Nuts four, fine] c-celli d and 

 (ingle-fccded. 



1. R. butyrofus. Leffer Suwarrow Nut. (Caryocar 

 Imtyrolum ; Willd. 11. 1. Pekea butyrofa ; Auhl. Guian. 

 t. 238.) — Fruit ffnooth. Leaves digitate, fmooth on both 

 fides. — Native of woods in Guiana, and cultivated at Ca- 



R H I 



yenne ; where it flowers in June and July, and bears fruit in 

 September. This lofty tree rifes to the height of eighty- 

 feet, or more, and is much branched at the fummit ; the 

 inner branches ered j the outer horizontal or declining. 

 Trunk three feet in diameter, with a grey bark, and reddifh, 

 compact -wood. Leaves oppoiite, digitate; leaflets entire, 

 oval, pointed. Flowers white, in large bunches, at the 

 extremities of the branches. Fruit yellow ilh. 



2. R. tuberculofus. Large, or Common, Suwarrow Nut. 

 (Caryocar tomentofum ; Willd. n. 2. C. nuciferum ; 

 Linn. Mant. 247. Pekea tuberculofa ; Aubl. Guian! 

 '• 2 39-)— Frilit tubercled. Leaves digitate, downy be- 

 neath. — Native of Guiana, producing fruit in July. This 

 tree differs from the preceding in having thicker leaves which 

 are downy beneath, and afh-coloured. Fruit larger and 

 tubercled, the pulp dry, not buttery. The nut is fweet 

 and palatable, containing a rich oil. Not unfrequent in our 

 fruiterers' (hops, and known by the name of Suwarrow Nut. 

 It is figured in Cluf. Exot. 27. f. 1, by the name of Amvg- 

 dala guianenfis. 



RHIZOMA, an appellation bellowed, by feveral late 

 authors, 011 the tuberous caudex, or body, of fome roots ; as 

 that of Iris Germanha, and many other of the natural order 

 of En/at a of Linnxus and Gawler. See Root. 



RHIZOMORPHA, fo called from its refemblance to 

 the branching fibrous roots of various plants, is a genus of 

 fungi, eftablifhed by Perfoon, in his Synopfis, 704. One 

 of its fpecies, R. 'fubeorticalis, figured by Micheli, Nov. 

 Gen. t. 66. f. 3, is called by that author, p. 125, Agaricum 

 nigrum reticulatum compreffum, e mortuis arboribus inter 

 corticem et lignum, mterdum in ipfo ligno innafcens,ac late fe 

 diffundens. Ray, Vaillant, and others, have likewifeconlidered 

 this fubltance as a fungus. Perfoon's generic character is 



" Creeping, rigid, fmooth, with a villous pith." 



He enumerates two fpecies befides the above ; fubterranea, 

 found among wet timber-work, in mines; andfetiformis, found 

 among dead leaves in woods. This lait is figured in Dill. 

 Mufc. t. 13. f. 11, b. They are all, to us, very obfeure, 

 and perhaps imperfedt productions. 



RHIZOPHORA, a Linnxan genus, whole name is 

 derived from fay., a root, and ipigu, to bear, or carry; the 

 feed germinating before it falls from the branches, and 

 fending dawn a remarkably long cylindrical root into the 

 earth. — Linn. Gen. 236. Schreb. 317. Willd. Sp. PI. 

 v. 2. 843. Mart. Mill. Did. v. 4. Juff. 213. Lamarck 

 Did. v. 6. 187. Illullr. t. 396. Gaertn. t. 45. Lou- 

 reir. Coehinch. 296. (Mangles; Plum. Nov. Gen. t. 15. 

 Bruguiera; Lamarck lllultr. t. 397.) — Clafs and order, 

 IXedeeandria Monogynia. Nat. Ord. Holeracet, Linn. Ca- 

 prifolia, Juff. 



Gen. Ch. Ca/. Perianth inferior, of one leaf, fpreading, 

 cloven into four, or more, oblong, acuminate, permanent 

 fegmenls. Cor. Petals four or more, oblong, fomewhat 

 fhorter than the calyx. Slam. Filaments fcarcely any, alter- 

 ter ; anthers from four to twelve, fmall, pointed. 

 Pifi. Germen fuperior, roundifh 1 llyle awl-ihaped, el. 

 halfway down, grooved at each fide; ftigmas acute. Parte. 



, nearly ovate, including onlv the hale of the fi 

 Seed folitary, oblong-club-lhaped, pointed, llelhv at the bale. 



Obf. The number in the parts of the Rower varies. 



Ed. Ch. Calyx four or live-cleft. Corolla of four or 

 five petals. Seed folitary, very long, llelh\ at the bafe. 



1. R. conjugoia. Linn. Sp. PI. 634. l'l. Zeylan. 81. 



— Leaves ovate-oblong, rather ohtule, entire. Col) x feffde. 

 Fruit cylindrical, awl-ihaped. — Native of India. /Ml that 

 is known of this fpecies may he gathered from the Flora 

 Zeylaniea, where it is deleribed as a tree whole leai>M arc 

 (talked, fmooth. Caly.ws twin. Fruit very long, pendent. 

 Y 2 2. R. 



