I 



ox FOiiSIL rol.YZOA. 



IVJ 



fig. -k 



fiff. ')■ 



fig. 0. 



Lower 

 Lower 

 Upper 



Family IV. LiiIIi;xii1mii;ip.i;, Smitf. 



= r>i'<rnpn;-i'hr^'l]nsk, ' 15rit. Cyclop.'; DIumpDri'Iluhv, Husk, ' ^^l;s. Cat.' 

 pt. iii. ; darrnhr, (p:irL) 'l)'( )rl). ; Tnhijorhlr^ (piU't) D'Orb. 



' /<i(M'//n/^ discoid, si:npli! or CDtiiiHi.sitc, iidnato, or partially iVoc and 

 Rtipitiitc. Zi)n'i-l(i tiil)uljir, nroot or siiluMvct, dispo.sod in nioi'O (.r less 

 distinct scries, wliich nuliato fV(nn a I'rcc (neutral area ; the intennediato 

 suriacc cancellated or porous.' — Jlineks, p. -in. 



Wlietlier this I'iitnily will i-eniain intact as we get a nioro perfect 

 knowledge of the structure of tlu; fossil forms below the Tertiary rocks, 1 

 ;im, at present, unable to say. It, woidd be unwise to displace the 

 'I'ertiary f mmiis that would naturally fall under thi.s head, and the few 

 ^Mesozoic species known to nu) tnay also lind a resting-place here, for 

 unless we knew morc! of the structure of the Jurassic species it would bo 

 also unwise to disturb tlie placement of these ; bub when wo c>nno to the 

 few disc-like forms of the I'aheozoic rocks, wo- meet with pocidiaritie.s of 

 f.lructure nnknown to mo in the more reccMit Ijirlii'iiopdriilir. Thive 

 species are described in the ' Silurian System ' as Dlscnpora, and ligured 

 ill IMate 15 of that work (tigs. '21, 22, 2',V) ; these are named: — 



Disr'i2)iim aiitiqita, !Milne-Kd. '; zzzCdli'ivtrn dutiijiia, Cioldf. 



Monhrtiiiijxino ,, ]51ain\'. 

 „ svpiamnfa, Lon.sdalo 

 ., ? fiivof^a ,, ^=Gellep()ra favam, Goldf. 



Within the last ft'W years the aflinities of these forms have been the 

 subject oi" ii good deal of controversy. \)v. Gustav Lindstrom ('Ann. 

 iMag. Nat. Ilist.' Ser. 4, vol. xviii. )). ', and se(jnel), in speaking of the 

 (levelopmcnt of MniiUciillpurii piffrnpiililiniii, i'auvier, says that — ' ft- 

 begins .... as a Ib-yo/oon, us a hix'-ninircll'i, or, as what, JIall has 

 termed CfninKipant, iuilirii-dfn (' Pal. N. Y.' vol. ii., p. 10!), ])1. xl., figs. 

 la-ii). There can be no doubt that this is closely allied to the recent 

 DUoporrlltt. (See Fr. Siiiitt, 'Ofv. Vet. Akiid. Forb. LSti'V p. 470, pi. xi. 

 tig. 4).' This opinion has been contested by Prof. Nicholson in his 

 work on the 'Tabulate Corals,' p. 2H'.), wherein he says — 'I have en- 

 deavoured to give a faithful account of the views Dr. Lindstrom hay 

 published as to the develo[)mont of the }rnnficah'pora,m\d npon which he, 

 in large part, bases his view that the fossils of this genus are really 

 Poly/.oa.' Since the publication of the works ' iMontieuliporidiV ' and 

 'Tabulate Corals ' of Prof. Xicholson, ^Ir. John Young, of Glasgow, has 

 'discovered specimens of another Bryo/oon, or Poly/.oon, as 1 prefer 

 to name it ... . that is (dosely allied to tlu; Siluriun C>'riiiiuiporit, 

 and which I have been enableil to follow clearly in all its stages of 

 growth until it becomes a true Mit)dicit.Jipin'a,' ('On the Identity of Cera- 

 lunpora niegastoma,' &ic., 'Ann. ^lag. Nat. Hist.' Dec. i8S2). The stages 

 through which this form passes before it assumes the Moiitiruhpord iovix. 

 are similar to, or prf)b;ibly the same as, the stages indicated by Dr. 

 Lindstrom — the FidiiUpora and Thei'oMiujafi'i^ stages. ^Ir. John Young, 

 however {Inc. rif. p. 43u), does not commit himself to give an o[)inion on 

 'the vexed question as to the zoological position of the organisms showing 

 tliese changes, bnfc only states that, as regards the Carboniferous form, one 

 of two things seems certain, viz., that if Fisf.alipo)Xi minor (AE'Coy) be 

 held to be a tabulated coral of the Montli'uHpioridia group, then Cemmo- 



