97 



do not know of any Palaeozoic forms of / with which this could be compared, and it 



i? readily separated from such form- U Defr ;,y the entirely different characters of th- 



cells, which approach closely in form to those of 1. and /'- ] 



largest trroup that I have seen Compi-i-.-- about twenty of the d; > -no -eia. mostly in 



contact but apparently in no wny connected with one another directly. 



/, ,//;/// ,///,/ Formation. Hamilton Group, liartlett's Mills, near Arkona. llosan,| 



lls. CERIOPORA (?i HAMILTCNKN>I< (Nicholson . 



'opora C' ) IIiiii>i/t. Nicholson), Geological .'.' \pril. 1>7|. 



Polyzoary ramo-e ; brunches cylindrical, about half a line in diameter, dividing dicho- 

 tomously at interval- of from a line and a hall' to three line-, tin- angle included between 

 each pair of branches l.ein^ about lu or ['t . Surface covered with oval, rounded, or sub- 

 quadrate cell mouths arranged in longitudinal rows, which are separated by delicate thr< 

 like lines. The cells of each row alternate with tho-c of the next row, so that they come to 

 be dispo->-d in regular diagonal line-. About lour r uuetimea tiv,-, occupy the width of 



the stem-, tin' cell- bavin- a width of alioin a tenth of a line ; and there are about five cells 

 in the space of one line, mea-uivd vertically. The interspace- between the mouth- of th. 

 cells are occupied by exceedingly minute tubuli. which form only a single row or are altogether 



-nt on the lines which bound the cells laterally, whilst they usually form a double 

 on the spaces by which the cells of a '_ r iveu row are separated vertically. 



/ 'Vii^'S' This beautiful little fossil occurs in great abundance in some of th. 



>;/ Bflti|* beds of the Hamilton Formation. It i- allied to th-- ' 



1 Hf$| (: "1'H'"~ '" ' ' ' '''''" I' 1 - I'XIV.. Fiir. li'jandto .]/ 



*' , Phillip- ) r > . Vol. II.. I'late I., Fi--. ;;i;-:: > iaU j to 



the former, but it i- di-tinLrui-hed from both by pcrfectlv 1:0,.-! and 



_nized characters. I am. at present, unable to decide a- r 

 true -etierie affinities, ami have simply referred it provi-i,,nallv to * 



1 pora on account -,f its close relationship to C Q fdf.)wh 



nat-ir.il likewise occurs in the Devonian Hocks-. 



... in j , .111-1 i 



/. .////// and rojTnatwn. Uommon in the Hamilton bormal 

 Widder. Township of 



m, I 'the tiilnilur in- 



Hul.ir int' 



Genus PTILODIOTT \ ( i-oi,-dale). 



" ( 'nrallum thin, oaloareous, foliai ir branching diohotomoualj ; branch.'- 



a thin, laminar. 11 iitcii,-,) r i.- iliy wrinkle,! c.-ntral a\i-. -t with obli,|iie 



:t -ub i i both -idc-. with prominent oval mouths nearly a.s 1. 



within . br.ii -ied. with tlie mar-in --olid, -bar; 



without cc'l- . the b iiindar', i ! '- -< |Uar.- or rli, >ml>oi.i , ^l < 



'I'he L-eiiii- /' o Loo iale ia identical \\ith > Mali, and indu 



q, of iMiriou- j which are esHcntiallj Silurian, but which extend into the I 1 



... .-Hid ap| into tin- ( 'arbonif,-! :,! Tli< 



r.oii eeiiulil.-rous -triated nnrjin : t,i I,.- ab-o. -ial or t,, |i,- unr. I 



].re-ent in the _'.-!! U- . and tlieeelllr.ll \\:> ptlllll. which -eparatc- tli,' r 



: .iiietim. -udinali- , ntrically wrink 



,u-. wliidi I cmiiot identil's \\ith an\ piv\ imi-h record 

 .tifiilly in the ( ',.rniter,.u- LIM. and in iy in tin- Hamilton formation 



'i I hit If: 



1 l!>. I'TII DDK I N l ' ' 



:/ , i/ M rol 



Polysoary having the form ui thin unch tlaf.n.d ellipticil i i 



I it), ,,)' :il>,iiit a line. a line and u h df or tw . l.n, - witli a tin 



7 



