104 CKYI.ON IT.AIM, OYSTKI: REPOR1 



(In- c..nlr:iHion of the former of which IIII.H, in almost all oawjs, completely closed 

 tin- aperture. Tli' diaphragm contains siijmala. lull, no ot,li(;r spiculeH. A similar 

 a i 1. 1 n^emen I of I he i - . I. i n;i I :i|ii-i I 1 1 res of the ca 11:1 1- sy: I i-iu :i ppea rs to lie eharacl cri t'\c. 

 hoth of , f wrica, :ui(l Sr/rri/ni/ri-ni'/ ,- indeed, our ( 'eyloii species, except lor t he absence 

 of micm si ron^yles, rcHcinlilc.M very closely indeed KcilMII/r'H Sfli:ri.li><l<-nii,n /"7a/v// 

 Iron i (In: (inH'oC Mexico, n,s drscriln-il ;md li^nrcd ly Sou, AH in II!H work on UK- 

 "Cli.'dl.-n^rr" THniHini-llid;.. 



I: N. 10 (Slnl. XV., Feriyii l';i:ir, Cull' of M;,n;,:,r. '.) f;,t IIOIIIH). 



Petromica, TOI-HKNT. 



of nuiasivc form; vvit.li Hcniti-rcd pores luid VCII|H; with tliin durm.-d 

 iiM!iiilir:in<- destjl.nt.c of H|xr<iml Hkclcton ; with motion i:|,id dcNiiiiLH f(!(:My unit-cd 

 or <|iiit,<! HujHinito ; with tnonaxonid rludidi often Collected in lilires whioliiniiy 

 li-riiiiiin,t) in Hiirllice connli ; wil.liout. mierose.leim 



iH WII.H founded hy Toi'HKNT in I H!)H (45) for ;i new Lithitid Bponge from I lie 

 AswmiH, vory dowdy related to Azori.cn,. TOTHICNT ^!VCH tlie following 



" A/.ol irii|;,. ni:i.HHivi!H, I'll I'onne de C.'.IM ". dre.'iMOH, .\ HIIlfiH'!' f!O|l llldlNC, il ])O1'CH ( 

 |\ OH(!llle:i nieinliriilieiix, ?l <'.to!-;oiiie (|e vcllopi' ;i,Hjiiruleil X , ,'l, dcHIIIJlH J)(!ll 



liiililenient I'olids entre eux." 



'I'lio diHcovery of .1 s.-cmid Hpef.icH in ( 'eylon wators, closely relnled t n the type of 

 I lie ^(tliiiH, forniH u furtlicr juitifioation for Heparid ,in^ I'ctroini- -n from I lie oilier 

 A/.oririd:i\ 



Potromica masBalis, n. KJ. 1'1,'dn IV., li^. .'. 



S|ioiiir,. in;i,SHive, liifi.y lie ;I||;M-|HM| |,y ;i, |,ro:id liii.He, m:i,y lie e,, ,m preHsed vertically 

 or liori/.ontiilly. VentH UHiiiilly iiiinicroim, ratlier Niniill, hut variahlc in M/A- ; 



-.illeled on I, lie ll|i|ier |>;irt of the ,S| inline, e;idi forming till! I rl'llll n;i,l,ioll of II 



vertiral oscnhn Inlie. POICH HCatterocl. SniT;i(-e uneven, v;iri;dile, morn or less 

 con-Mealed ; in |il;icew ci ,vi:red with a thin, reticulate, pore hearing dermal iiieinhrane 

 overlying lar^e Hlll)-(lorinal c.ivilies ;md snp|iorted on lnmdles of hn^e iiionaxonid 

 ;;picnles which soinetinies terininaie in coinili. T< I nre incompressilile, hut friable ; 

 colour (in Hpiril) ydllowiHh ^rey throiii^honl. 'I'he type .speciinnn (It.N. 2. r )7) nmasurcH 

 ahout :i7 milliniM. in height, the s.nne in hre.-iill.h, .mil '.' I niilliniH. in I hi(-l<ncHS. 



Tho main skeleton is a rel icnlnt ion (some,t,imeM (;lose, a,nd sometimes so loose th;it 

 t he desmas do not l.oiicli one ;inolher) of much branched monocrepid desmaH, intcr- 

 iinnidod with nimieroMH lar^c mona.xoniil Ipiculei which ;i,re partly collecled to^ntlu!! 1 

 in coai-Mi- liliren (without hcin^ united to^ntJier hy iiny cementing sulist-ance). 

 'l'h(!HO lihr(!H, aw already noticed, .sometimes terminate in surface conuli. Then! is 

 no special dermal skeleton. 



Sjncules. (I.) Monocrepid desmas (I'lale I V., li^. . r ), ff) ; much and \ery irregularly 

 hranched ; not tnherculatn (or very slightly so); hra.nchcs usually tcrniiii:i.fiii^ in 

 short, hliinl, romc.-d pmnls, or in curved flattened e.\|ia.nsioiis j)ressed ugailiHl other 



