21 



so as to form a central boss or projection. Radiating -cpta numerous (from eighty to on 

 hundred), varying much in the extent to which thfy encroach upon the central tabulate area 

 External area thin, vehicular, it- cells formed on the one hand by the septa, and on the other 

 by u series of curved plates, which extend in an arehinir manner and in a direction nearlv 

 parallel with the axis of the coral, obliquely from the central area to the epitheea. Wh--n the 

 epithecu is removed, the apertures of the cells of this external area appear on the surface in 

 the form of rectangular openings directed very obliquely inward-;. In -pecimen- in which 

 the epitheca is prc-i rved. the .-nrface exhibits encircling ri<Le< and annulations of <_Towtl), 

 varying much in their comparative rei:K''en"-s sometimes rounded, sometimes sharp-edged. 

 There are also numerous costae, varying from four to MX in a space of two lines in -peeimen- 

 of different sizes. A well-marked septal Ib-sette can usually be detected. 



As already remarked, the internal strueture of this species d >es not eonfnrm with the 

 definition of C iven either by Edward- and Haime or McCoy ; audit seems 



doubtful if it can be retained in this L'enus. In mo-t re-peet- the .-peel.-- eomea nearest to 

 the characters of A/nj"'- . but it i- distinguished by the pre-en,-,- of a cone and the po- 

 sion of an external vesicular area. The cone or central boss is certainly, formed by an e! 

 ti"-> ..f the tabuke of the central area, and the condition of the septa vane- very much in 

 different examples which appear to be otherwise referable to thi -. Sometime- the 



septa extend as far as the centre of the coral, benn: continued aero-- the upper -ur 

 the tabula- in a dimini-hed and rudimentary form. Such examples would, perhaps, come under 

 tl, ! inition of i lisiophyttum given by Milne Edwards and Haime. More commonly, tin- 

 sept ;i are comparatively rudimentary, and .extend but a short distance from the outer wall, 

 leaving the central tabuhe exposed, very much as occur- in Ai. 



Examples of this specie- t'roin which the epithec-i has been removed, may u-irdly be 

 determined by the peculiar rectangular and obliquely-descending cells of the outer ve-ieular 

 area. It niu-t be admitted, however, that if the internal strueture i~ nut shown it i- some- 

 time-; di;ficult to distinguish such specimens from examples of /,'/"/// ri^mi/llma d ''tm 



which have been denu .a to the central core. 



/. F Nol mmon in the Corniferons Limestone of Port Colb*orne, 



and Very abund int in the same formation at llagersville. 



10. <'i.Mi>rilYI.!.rM ri.rKIKAIilAI.i: (Xiel; 



Corallum sim[>!e. fcurhinate or oylindro-oonio, straight or curved, of larj-- 1 size. <''-ntral 

 ar.--i t-ibulate, the fibiil.-i- .stroji i'. i'orm a median bo-- or proj.-etion. K idiat- 



itiLr -'-pta exe.-ediirjly nunieroii-, alternately ]ar_'e and -mall, beinu' about ...... lundred and 



twenty in -peeimen< of an inch and a hall in diameter, and ri-inu' to one lumdred and ei^litv 

 in a -pceinifii two incbe-, and a quarter BOrOSa 'I'll'' .-'-pta extend a eon-id'-rable di-taiiee 

 inward-, and a -ept'd ti.ctti- i- i>r.----nt. Surf ..... m irked with mim-Toii- rounded eiieircliiiu' 



folds and annulations. and al-o with -tn>n_' ami nnu-nallv well marked .-ejital rid'_ r e<. ah. nit 

 four of which occupy a Sp&OG of two lim--. DimensionB unknown, but '_re it. larje -peeim 

 having a leiiL'th of half a foot or .nor-- and a diameter ( ,f nearly two ineh. - and a lialf. 



Thi--: irly separable from (7. ( '' ;. r dimen-ion-. 



the mui-ii greater number o| jt~ ,-epta in cxampli-- of -imilar dimen-i.m-. the ab-ene.- ni 



external vesicular area, and t'l-- surface characters, Whether it i- truly referable to the 



Hum, howevr. may !" r.-j-irded afl very doubtful tin- central ele\ation. a- in 

 C. ' , beiirj clearly formed b\' the tabula- al^ne. 



/. ''/ 'in'/ I Not uncommon in the ( ', mil'. M.II- Lime-tone of \\\ '; 



<! '/. \ I-IIILI.N I 'i- i i;:itim-,|ii . 



1 rallum simple, turbinato or cylindrical d--cp, with a I 1 



occupying the pi ..(' th ..... pta ; no columella ; t 



upon tb.-ir lipper -url'iee i. whieli . \t. IP! fr..m tin- epitbeea. m-arl\ r 



to the e. -nti-e nf the rorallmn. Th-- i;i 1 lo.-uli n-iril'v uninternn | b\- 



the t d.ul-i-. but lometimee interfered will tncntc at tl. "I" the coral, 



givitiL.' ri-e to an outer an-.i of ve-ieular ti 



The geOUB Zaj -!' I! if'n. .pi.- \+ identical with the -jenn- ' of Mieh.-lin, 



and i- on,- ,,f th,. QJ ,,f tl,e ('vathoph\! : U Ti.e | ' form- 



