17 



cate layer in which the pores were perforated. The granulated layer which appears to form 

 the surface in so many specimens, would thus appear t<> have been covered by a kind of " der- 

 mal " membrane, and to have permitted a tree circulation of water over its .-urface, the irra- 

 nules beiiiL' more or less confluent, and -ivin^ ri.-e to a complicated system of sinuous or ver- 

 micular horizontal channels. 



In a great many specimens the surface layers exfoliate round numeroii- points -/u iti'_ r 

 the upper surface of the fos.-il ijuite a characteristic apiiearauee, whieli is wanting in > 



Generally speaking, . grnti//!,if,i may be distinguished from >'. tuberculata, to which 

 it is nearly allied, by the more delicate character () f its retieulated tissue, and by the far that 

 the minute crowded tubercles which cover the surface are so closely [.laced as to be nearly in 

 contaet. A< a rule the species occurs in the form of rery extensive undulating crusts, on/ 

 specimen observed by me covering a slab al,,,:,t three feet in length. by two feet in widtj 

 with an average thickness of half an inch. I pos-e--, however, cue evamp!^ in whieh t' 

 organism is attached by a broad base to a bage Heliophyllum, from whieh' it spreads 

 laterally in all directions as a horizontal expan-inn. the under surface bein_' cover- d v- i l 

 wrinkled cpitheca." and havintr obviously been free. 



1- d formal . Not uiieoiiiiuou in a >ilicified condition in the Connl'er,,: 



stone of Ridgeway, Port Colborae, and Savage's Quarry, Wainfle ll " u 



formation of Uo.-aiicjiiet, at Bartlett'.- .Mills, near Ark-ma. 



j. STKOMATOPORA MA.MMII.LATA (>,"icli"l>.,n). 

 "(Plate I., Fig. 4.) 



&//, fl iniiiiniiilhita (Niclml-uii,. Aunal- and .Ma-azine of Natural HPT- -\ u --- 



1873. PI telV., 1 ig. 4. 



1' - ;nin- tiiin cru>t-, about two or three lines in thickms-. often coy,.' 11 - ' xtl " 

 surl'ae.--. Crnsi e.impo-.-il of SUCC' -'meentric calcareous lamin;.-, separateiK v '"'''' ~l' :l ''' " 



and broken up by vertical dissepiments. Surfar.- undulating and .xhibitiiiLT Sl ' r i'"' "* 

 conical elevations about one tilth of an ineli in hei-ht and the same in diaii/ l ' r :it ''"' '' :1 



placed at distances apart varying from one fifth of an inch to half an ine' M"-t ^t tl 



OOnical elevations show no Signs of beinL r perforated ; but M. me appear toiav" aperture-* at 



faces between elevation^ a> V ,- e .:'ti''ii> tl.em-eh 



ll -ummit<. The BUrfaces between these elevation^. a> \ V ,-H B & the rl,.:'ti''ii> 

 arc roughened with numei-oii- -mall ^ r ranule<. tubercles and irre-ular. sin'" Us ri : 



ild be m,. iv di.-tinet than th.-a-pect of this very remark/ole species, tlie 



i-oiiic-ii i:.- which cover its .-urfac,- -ivinir it exactly the appea/auee of an undulating 



plain OOV( r.-d with .-mall volcano,'-. Sup. i-lie'nlly examine, l] it present/a striking reseaiblai 



toman. sponges; but it cannot be asserted positively that the conical elevations jut 



alluded . :' the nature of o-enia. Some of them oertainjy look as if tbq were] 



forated ; but mo-t -bow no signs of any aperture. Thk boweVOT, i- \'ry pr.-"bl\ due to 



. 

 the manner in wh.eh the fo--il ha- be.-n |,|, }erved ; and tin- anal,- v of >'. -/, WOUld leM 



one to conclude thai the conical elevations of gf. mami ure truly OBCul* ''"' internal 



f all the examples which I possess of this species i- much mor- imperfectly] 



:v.-rved than i.> ill,- Case with the other BpCCiea ben- ,\, -eribe.l ; and 1 lr u ' >i'i'l"> l " 1 ' 1 ' ;i ''''' 



to sati-t;, m\ , If that it is essentially the sam< baracteristio of ' 



ba 1 .,- wen ITU-I* of ihi> .-[ . :i | ^juare fc- : but it i- by no means 



oi>mnii,n in i: - oreurr, nee. 



/. /'-/ a, 'I/inn. Kare, in a >ilieili.-d c,,ndition, :.i the ( Wii'ifer-m- lime-- 



1'ort ( 'olborne. 



BTBOMATOPOB \ . ni'-x ( 



In aiMi:i,,n to tb,- p; . ,1, -crib,-, 1 -peei, -. tin-re oreiir iu the CoraiferOQJ lii' 



ofWe-tern Ontario -p, eim, n- whieh a , hardly or n->t at all distinguishable Iron, - 



; Qoldfu A I n or, all of thM6 peotmens are fragmentary, and non 



them exhibit tb.-ir -url'ic,-. it can not ! p,,.-itivel\ averted that they : 10 thi- t.un. 



pad . 



Locality and tformaJtofi. Oorniforou l.ime-t,.n,-, r,,rt ('oll,,irne. 



a 



