1 



OOLITIC SY8TKM. 



OPHIDIA. 



H 



. uwdes. 



/a. Phil. 

 TWw MrfaM*) ( r), Sow. 



M, SoW. Sp. 



13.p~i. 

 {.'10 JufoiVHj, Bean. 



i A'ucWn/ormu, Roemer. 



G*rO/-, 10 tpaci.* 

 Or^AM. U i|MaiL 



/OTMIU, 3 **ciM. 

 /...a. < ipMM*. 

 /..- JtjJieatt, Ooldf. 



Cm**) Mfiga'inr. Jell v. 

 iU-rtte AMHM, Phil. 



* 



(Mr**, 1 sped**. 



/ - 



riayiottoma, 10 species. 

 Plitalula, 3 ipecies. 

 fipondyliu nmpliu, Goldt 



!} n - 



Sfiriftr, 5 tpecie*. 

 Teretra/K/a, 43 specie*. 



Cxiittropoda. 



CVnu,S*p 

 /Am/Win*, S spsoiat. 



. cincla, Phil. 

 r,tjl<u, 2 specie*. 

 PltHrotomaria, 11 species. 

 iUii dolhrata, Sow. up. 

 foa, 4 species. 

 Rotttllaria, 3 specie*. 

 &rfUa, 4 specie*. 

 SotanW calyx, I'hil. 

 TVirfcra, 8 ipecie*. 

 7"ixx-Aofoa u/ca/a, Lye, U. 

 TVoeAiu, 10 specie*. 

 rroo, 4 specie*. 

 Turrildla, 1 specie*. 



Ctfltaloptda. [CEPHALOPODA.] 



/w. [FISH.J 



( AMUd, Bfmtmlary Otology: Tennant, Stratiyraphieal Lift of Ilriti,!, 



S 1 spaaiM. 



SJMCM*. 



JY.rer llanatiuu, PbO. 

 Afofm, 10 ( 

 .Yrn'mra, < 

 AVrita, 6 



, 5 iMcfe*. 



ITIC SYSTEM. [Ootmt] 



OPAL. Of thi* mineral, which U essentially a hydrate of silica, 

 that* are meoliooed by Mr. Brooke, in th ' Encyclopaedia Metro- 

 politan*,' eleven varieties, and nearly u many are described by 

 Phillip* 



Prtrunu Opal, at ffoblt Opoi Tbi* mineral u white, bluish, or 

 y*Uowih whit*. and exhibit* a beautiful variety or play of ooloun, as 

 Uo, grata, yellow, and red, several of which appear together. Frac- 

 ture conrhoUUl, with a vitreous or reainoua lustre ; it ii easily broken, 

 bat ontebe* gW Spwiflc gravity 2O6 to 2-09. Infiuible by the 

 blow pipe, but become* opaque and low* water. The mart beautiful 

 ' M occur in Hungary, but it ban also been fun<l in Saxony 

 America, Ac. Analyst* of the Hungarian opal by Klaproth : ' 



! . . .80 



Wa.se ......... 10 



100 



the Internal reflection i* bright rod. It occurs 

 witb tha Precioui Opal in Hungary, and hai also been found in 

 Cornwall. 



1/fdrftJtmmt. It i* unully opaque, but is rendered transparent, 

 and xhikit* the irldamnt colours of the Precious Opal by immersion 

 in water. According to KUprulh it contain" a little alumina in addi- 

 tion to *Uic* aad water. 



OBBMM* OfuL Tbl* U of variou. shade* of colour, as white, green, 

 nliow, and r*>) ; but U entirely dwtitato of the play of colour* exhi- 

 bited by the Noble OpaL In oil. . they greatly resemble 

 aeb other. It I* stated to contain a little oxide of Iron mixed with 

 tb* Mile* and water. It i* f.xin.l , !,,. ily in Hungary and Saxony, but 

 pactoMM b*v* also been produced in Cornwall 



*<-'>/. -TJiU i* more opaque than tha Common Opal, and i* 

 Ml. It oooan either white, gray, yellow, brown, or green. It is 

 fBMd ! tb* sun* pUoM a* the foregoing. 



KW'>a/, to called from iu showing the woody structure. It 

 occur, of eavwal tint* of white, gray, brown, and black. It is gene- 

 rally baHar than tha Smi-Opal, but doe* not materially differ fn.m 

 it la oW properOe*. It occur, in Hungary and In Traiuylvanla. 



OMtaim i* white OMqtU opal ; harder than the Common Opal ; 

 dull; bntO.; tractor* flat ooooboidal Specific gravity 2-J. Infuible 

 Man UM blow.pip*. U i* fonad on the bank* of the river Caoh in 

 lo*> nuatii. It occur* also iir the Faroe Inland*, Green- 



oBlbeeHRw. Conor 



> 



It, ocean la Hoofarj. 



from T*lkrl*nya gar* 



U 



Uep shade* of red, yellow, and gray. 



nan to be a silicate of Iron with water. 



*c. KUproth. anlj.i. of a variety 



Silica 43-5 



Oxide of Iron 47'0 



Water 7-5 



Menilitt, It occurs in irregular or reuiform mosses. Colour usually 

 smoke-brown. Opaque, or slightly translucent It occurs at M.-nil- 

 Montant, and St. Ouen near Paris, in bed* of adhesive slate. Accord- 

 ing to Klaproth it consists of 



Silica 85-5 



Alumina *> ' ' 



Water, Inflammable Matter, and tracH of 1 



Lime and Iron j 



-97-5 



Hyalite, Mailer t (ilau.It occurs in small globular and botry.'i lal 

 forma. Lustre vitreous. Brittle, but scratches glass. Specific gravity 

 about 2'4. Infusible by the blow-pipe. It occurs in amyp 

 Krankfurt-on-the-Maine, in Hungary, &c. According to Ilucholz it 

 consists of 



Silica, with a trace of Alumina . . . 92'0 



Water . 6-3 



98-3 



Gti/terite, Silictout Sinter. This mineral is white, or yellowish or 

 grayUh-white. Brittle. Specific gravity about 1'SO". Infm-ible per 

 ?e by the blow-pipe. It is deposited by the hot-springs of Ir. land and 

 elsewhere. According to Klaproth it consists of 



Silica 98-0 



Alumina 1'S 



Iron '5 



100 



OPEN-BEAK. [HiAKS.] 



ul'KUrri.lTKUA, one of the families of Polypia inarra 



of De Blainville, also called Etchariaa. 



OPEK'CDLUM (Malacology), the plates or pieces which protect tho 

 apertures or exposed ports of ceitain Molluscs. In many of th 

 taceous Gastropods it becomes a cover or door, which (its t 

 of the shell more or less accurately when the animal has retired wit MM 

 it. Opercula of this kind vary much ib structure and nlmpc. Thus 

 they are sometimes horny, as iu Trochu* and Mures; om 

 shelly, nay almost stony, as in Turlo ; and in construction they are 

 for the most part either spiral, concentric, or unguiculated. 



In Botany this term is chiefly use.l for the cap which forms the 

 upper extremity of the theca, or sporangium, of a moss, covering over 

 the peristomc, and usually falling off when the spores are ready for 

 dispersion. It has also been applied to the lid which covers iu the 

 Pitcher of Nepenthti, where it is the lobe of a modified leaf. 



OPHIDIA, on order of Reptiles without feet, and consequently, as 

 Cavier observes, more deserving the name of Reptiles than any -other 

 order. 



According to Cnvier, the order Ophidia consist* of the genus Angult 

 [T.i IMIWORM], of True Serpents, and Naked Serpents. Cuvicr's second 

 family, or that of the True Serpents, comprehends the genera which 

 have no sternum nor any vestige of a shoulder-blade, but who 

 still embrace a great part of the circumference of the trunk, ami tin- 

 body of whose vertebra ore also articulated by means of o convex 

 surface which is received into a socket or concavity of that v. . 

 which succeeds it. They want the third eyelid and the tympanum; 

 but tho ossiculum auditus exists under the skin, anil its shaft or handle 

 (so to speak) passes behind the tympanic bone. Many have v 

 of a posterior member under the skin, and the extremity of this 

 rudiment of a limb shows iUelf externally in the form of a small hook. 

 [Bo I DA] 



Those serpent* to which the names of Doubles Marcheurs, or 

 Ampkubanidft [AMPHUBXHA ; Trm LOPS], have been giv. n, l,.u> ih,- 

 lower jaw carried, as iu the Tortoise* [CHKI.ONIA] and Lizai 

 by a tympanic bone which is articulated directly with the craninni, 

 the two brunches of that jaw soldered anteriorly, and those of the 

 upper jaw fixed to the cranium and the intermaxillary bone, 

 their mouth cannot be dilated, aa in Cuvier'a next tribe (tl: Srq.< IIM 

 properly so called), and their head is of uniform si/o with tlu-ir body ; 

 a form and structure, which ensble them to makepm-n . . iMpmlly well 

 in both directions, head or tail foremost. The bonyframe ..i" thi'. n-liit 

 is incomplete backwards, and. their eye is very small. Their body is 

 covered with scales, the anus very near its extremity, the trachea long, 

 and the heart placed Tory far backwards. Of this' tribe no ven 

 ipecie* are known. 



The Serpent*, properly so called, have the tympanic bone, or ). 

 of the lower jaw, moveable, and nearly always suspended to. an.>! h r 

 bone analogous to the mastoh ! t > i!, < ramum liy muscles 



and ligament* which permit its mobility: the branches of t! 

 are not united to each other except by ligaments, nor are those of tho 

 upper jaw united to the intermaxillary bone in any other mam 

 that they can bo more or less separated ; a conformation whirl 

 these animal* the power of dilating their mouth to such an ev 

 to enable them to swallow bodies larger than thi-mmlvex. Th. ir 

 palatine arched participate in thi* mobility, and are armed with ] 

 teeth curved backwards the most marked and constant character of 

 I thi* tribe. Their trachea is very long ; their heart situated very far 



