Section IV., 18!'2. [ 39 1 Trans. Koy. Soc. Canada. 



III. — Oil ihe Corah and Corallifor m Types of Palnozoir Strata. 



By E. J. Chapman, Ph.D., LL.D., Professor of Miueralogy aud Geology iu the 



University of Torouto. 



(Read June 1st, isitj.) 



Among the fossil forms of post-palœozoic date referred to the Anthozoa or Corals 

 proper, very few, if any, occupy a debatable position. Many of the commonly admitted 

 palaeozoic corals, on the other hand, are of more or less doubtful character, aud have thus 

 been placed by some authorities under other subdivisions. Whilst admitting their uncer- 

 tain affinities, however, it seems impossible to separate these doubtful types on any really 

 satisfactory grounds from the more distinctly coralloidal forms, into which, indeed, they 

 appear to merge by almost insensible transitions. Iu this paper, therefore, the term 

 " coral " will include all the generally recognized coralloidal types of palœozoic 

 occurrence. 



The great division of the Ccelenterata, to which the corals belong, is usually sub- 

 divided into three leading classes : — Hydrozoa, Anthozoa, and Ctenophora. The latter 

 class, represented by a small uumber of pelagii\ ciliated types, is an entirely aberrant 

 group, and is without any known fossil representatives. Living Hydrozoa are distin- 

 guished from existing Anthozoa by no very certain characters— many of the supposed 

 distinctions, at one time regarded as characteristic, having been shown of late years to 

 be more or less indefinite ; and it is extremely probable, as suggested by the late Professor 

 Agassiz, that the so-called " tabulated corals " should be referred, really, to this class — 

 the Hydrozoic Millepores forming the connecting link. These tabulated corals, again, 

 offer iu many cases a complete transition into the tabulated Eugosa,' the assumed tetra- 

 raerous character of the latter being in many instances, as shown farther on, either with- 

 out foundation or entirely unrecognizable. It would .seem advisable, therefore, in place 

 0Ï three, to adopt /ù'e leading subdivisions in the classification of the Cielenterates gener- 

 ally, as in the annexed tabular synopsis : 



A. — Without natatory cilia. 



A.^ — Stomach cavity completely identical with body cavity : 



{i). — Without stony corallum : 



Class I. Hydrozon. 

 (ii). — With calcareous (typically tabulated) corallum : 



'As exemplified, for example, by the following series:— Farosiles—Columnaria—Amplixus—Zaphn nth— 

 Cyalhopliytlum. 



