Section IV., 1802. [ 39 ] . Trans?, lioy. Soo. Canada. 111. — On iJic Corah nnd ConiUifor in Types of Pahtozoh Stilumnnna—Amplixuf — /uphr' ntis — ( 'yiithophiillum. 40 E. .1. CHAPMAN ON TIIH CljAt-'S II. Hijdrucoralhi. A.- — St'UiiacJi partially separated from body-cavity. (t ) — Oro-aual orifice with eight fringed tentacles : CiiASS III. Alcyimaria or Crossoro^ratla. (ii) — Oro-iinal Drilice with luimerous simple tentacles. C'unillum e^ss^'lltially iioii-tabulated, but with distinct septa ; Cj>ASS IV. Zonntltaria or Anlhocordlht. B. — AV4th natatory lilia : CJiAS8 V. Ctenoplioni. The present commuuicatiou refers essentially to the second of the above named classes — that of the Hydrocorali-.\. This includes the Hydro-CoralJimc of Moseley, together with the so-called TabuJata and Riigosa of other classifications. In the present state of our knowledge it is necessarily to some extent a group of convenience, connecting the Hi/dro:t>u with the typical corals. The Tubu/ata in many classifications are widely separated from the Riigosa, and placed with the ordinary " Hexamerous Corals :" although, from the absence or rudimentary character of septa in many of these forms it is not pos- sible to tell whether the tentacles of the living animal were hexamerous or otherwise. The Rugom are also for the greater part essentially tabulated forms ; and although, commonly separated from the Tabulata under the name of Tetracoralla, the actual number, of septa iu many cases is either indeterminable or exceedingly variabb'. As examples of variation iu the number of septa in both the Tabulata and Rugosa, the genera Sli/lina, Lamarck, Sti/loarnia, Edwards and Haime ; Helero/ihylfia, McCoy ; Diincanella. Nicholson, and many others, may be cited. The descriptions of many Canadian species by the late Mr. Billings, a most minute and trustworthy observer, also lubstautiate this point, and prove that, although very convenient on paper, the distinction (except in certain well marked cases) is virtually of impossible application. And again, we have no certainty that the number of septa or septal markings really indicate the number of the tentacles possessed by the living animal. In the living Mi/le/)ora, for example, the researches of Moseley have shown the presence of eight tentacles, as in the Alcyonarians. If therefore, as commonly assumed, the fossil HelioUtes be regarded as a closely related type, its twelve septa or ' pseudo-septa '" are entirely misleading. Many of the forms placed under this subdivision in the present synopsis — espei ially those of the three first sections given below — may very probably belong to the Ahyonaria or to the Bri/ozoa; but this view is entirely conjectural, and cannot at present be either l>roved or disproved On the other hand, the strikingly tabulated structure, so charai- teristic of the great majority of these forms, serves to unite them conveniently, and, in the absence of negative evidence, naturally also, into a common oroup. The class HviiROCOllAT.LA, as here adopted, may therefore be defined as follows : — Hydrozoa or closely allied types with calcareous corallum. The cells of the latter eithor CORALS AND CORALLIFOL'M TYPES. 41 (iutirely destitute of iuterual structures, or coutiiiiiiug in the great majority ol" oases : (1) well developed tabula-, with or without radiating septa ; or (2), vesicular tissue with or without tabuhe and septa ; or (3) a distinitly hexamerous or tetranierous system ol" septa ; or (4) iudicatious of bilateral symmetry. The class, as thus defined, may be subdivided provisionally, and especially for deter- minative purposes, into eight leading sections, as in the following scheme : Corallite cell entirely empty, i.e., witnout any internal structures : v^ 1. Vacuata (Type form, Aiilopora.) Septa absent or quite rudimentary ; tabuhe well developed : § 2. Tabtti:ata (Type form, Farosi/ts.) Corallites united by a tubular or cellular c(i>nenchyme. s^ 3. Cellulata (Type form, Fislulipora.) Tabuhe and septa both present. § 4. Tabulo-Stellata (Type forms, Amplex/is, Zuphrenlis.) TabuliB central only, surrounded by area of vesicular tissue. Septa well developed : § 5. Vesicut.o-Stet>t,ata (Type forms, CyalhnphyUum, Lonsdalia.) Tabula- entirely replaced by irregular vesicular tissue : k 6. Vesiculosa (Type form, Cipiipfii/t/um.) Cell provided with an operculum composed of a single valve or of sevt-ral valves : § 7. 0PERCUr..4.TA (Type form, Calceola.) Cup or cell containing septa only ; tabula> absent : § 8. Inteqri-Stellata (Type form, Pelraia.) § 1. Vacuata : — The representatives of this section, distinguished essentially by their tubular cells being entirely destitute of internal structures, an- of very doubtful position. Very probably, they should be referred to the Alcyonaria or placed near the Serlulariaus under the Hydro-medusa- : but nothing delinite, it is obvious, i-an be determined on this point, and as the forms in question are of not uncommon occurrence in pakeozoic strata, it has been thought advisable to retain them here, at least provisionally. They form but one family, that of the Anlojwridir, (-ontainiug the following gimera : Fam. Aiiloporida; : — Corallum composed of short, tubiiiar or funnel-shaped empty cells, united in branching groups : Sec. IV.. 1892. (I. 42 B. J. CHAPMAN ON THE Aulopora, Goldf., Sil, Dev., C!aib. Reptellu, Rolle, Sil., Dev. Cladoconus, McCoy, Carb. § 2. Tabulata. The corals of this section are distinguished by the presence of numerous transverse tabular in their component cells, coupled with the absence of r idiating' septa, or the rudi- mentary, imperfect character of these when indistinctly present. They have been separated widely in many systems, and have been allotted partly to the Alci/onaria, partly to the Bryozou, and in part also to the Riigoi^it generally. Whilst thu.s manifestly occupy- iug an uncertain position, the two fundamental characters given above — namely, the presenci' of tabuLe, with absence or merely indications of septa — are sufficiently definite to warrant their retention in a common group, and to show at the same time their relations to the coral forms of section -1. in which botli tabula' and well developed septa are present. Th(! more typical i-epresentatives, including all the better known genera, may be arranged under six families, as in the following synopsis: Fam. 1. ClKclelidie : — No cceuenchyme Corallites, capilliform, or of small diameter, C/uctetes, Fisch. (including MonlicuUpora and Slenopora), Lr. Sil. to Trias. Tetnidium, Satford. Lr. Sil. Fam. '1. Bedianoidithc : — No cteneuohyme. C'orallites comparatively large, polygonal, with imperforate walls. Beaumontin, E. & H., Carb. Fam. o. Favuaiddte : — No coenenchyme. Corallites, polygonal, round or crescented at surface, with perforated walls. G-roup A. Plant. — Tabulte horizontal or inclined : Favosites, Lmk., Sil., Dev., Carb. Columnipora, Nich., Lr., Sil. Alveolites, Lmk., Sil., Dev. Pachypora, Linds., Sil. Nodulipma, Linds., Sil. Group B. Timidi. — Tabula; convex or more or less vesicular : Emmonsia, E. & H., Sil., Dev., Carb. ML'helinia, de Kon., Dev., Carb. Fam. 4. HalysUidie : — Corallites lubular, imperforate, connected only at opposite sides, typically in chain-like aggregations. Tabuhe, horizontal : .: Halysiles, Fisch., Sil, Thecostegiles, E. & H., Dev. CORALS AND CORALLIFOEM TYPES. 48 Fam. '). S//ringo/>orid(C : — Corallites tubular, imperforate, coniiocted by short trnns- vprse processes or by lateral expansions. Tabuhe, funnel-shaped : Sf/ri)/i:^oporn, Gold., ]")ev., Carb. Hdinifo/iliijllum, Bill., Dev. § ^. CELTiULATA. Tliis settion. like the last, comprises a series of coralloidal forms of very doubtful l^osition, but conneeted with the Hydro-Coralla irenerally by the presence of numerous tabuhe; and in one of the two families, into whi(^h they are subdivided, by distinct septa, or " ps<'udo-septa." They are made up of capilliform or narrow tubular coralli- ti's, traversed by septa, and connected by ccenenchyme, in itself composed of minute, tabulated lubes, the whole .somewhat resembling the surface of a sponge in which the ( orallites represent the oscula. Some have been given to the Bryozon. Others, from their supposed relations to the modern Heliopwa, have been referred to the Alcyonaria ; but it seems better to leave them among the HyuRO-CoRAT,iiA until more certain evidence is obtained of their true affinities. They may be subdivided into two families, with gejiera as follows : Fam. 1. Fistuliporidce : — Corallum compound, composed of minute corallites with surrounding capilliform cconenchyme ; both tabulated, but without septa. Fistulipora, McCoy, Sil., Dev. Cullopora, Hall (scarcely differing from Fistulipnra), Sil., Dev. Fam. 2. Heliolitidce : — Corallum compound, composed of small corallites separated by a < ellular or finely tubular ca-nenchyme ; both tabulated ; the corallites showing twelve short septa or pseudo-septa around their inner margin. Heliolites, Dana, Sil., Dev. Lijellia, E. & H., Sil. Plasmopora, E. & H., Sil. Thecia, E. & H , Sil. § 4. Tabulo-Stellata. The corals of this section are characterized by the presence of both tabula3 and septa. The tabulce extend in typical examples entirely across the corallite-cell, but indications of an outer area of vesicular tissue are occasionally observable. The septa are marginal or short in some cases, although always distinctly developed. In other cases they extend into the centre of the cell, and form by their union a twisted pseudo-columella. The typical representatives form three families, as in the annexed tabular distribution : Fam. 1. FavistelHdte : — Corallum compound, with hexagonal or polygonal corallites in close juxtaposition, much resembling Favosites ; but walls imperforate, and distinct septa (short or long) always present. Columnaria, Groldf., Lr. Sil. Favistella, Dana, Sil. • 44 E. .1. CHAPMAN ON THE Fam. 2. AmphrxkhB : — Corallitos tubular or reed-liko, typically with short or marginal septa and extended tabulic. Amplexus, Sowerby, Sil., Dev., Carb. Calo/)Iu/l/um, Daua (int-ludiug Cynlho/ilii/l/oides), Sil. ChonopJu/l/iim, E. & H., Sil., Dev. Fam. 3. Zaphrentidic .— Corallum simple, turbinate or horn-like, with well developed tabula? and septa. G-roup A. — Connciilali (simple, horn-like forms) : '/Aipln-entU. Rat', (including Anisophi/l/um and PenlaphyUnm), Up. Sil., Dev., Carb. Ptj/co]ilii/llinn, E. & H., Sil., Dev. Slreptelasma, Hall. Under this genus, the forms o{ Zaplirentix with marked pseudo-columella may be appropriately placed. Sil. G-roup B. — Columniferi (with distinct columella) : Loplioph/jlliim, E. & 11., Dev., Carb. Group ('. — Cniciferi (primary septa forming a distinct rcctangxilar cross) ; Phri/ganophi/lfum, dc Kon., Carb. Group D. — Bi-formes (septa showing a twofold mode of arrangement) : MenophyUvm E. & H., Carb. § 5. Vesiculo-Stellata. This section is more or less closely connected with section 4, but is distinguished especially by the contracted dimensions of the tabula*, and the replacement of the outer portion of these by an area of vesicular tissue. Hitherto, many genera of these corals have been made to incli\de both simple and compound forms, as well as types of very dissimilar couliguration ; but in the present distribution I have ventured upon an inno- vation in this respect — believing, from the examination of numerous examples, that a generic separation of the compound tesselated forms on the one hand, and the sub- aggregated, reed-like and cylindrical types on the other, from the essentially simple forms, is warranted on natural . .ounds, and is conducive to a more ready determination of genera, as well as to clearer and sharper definitions. In the present distribution these vesiculo-stellate corals are arranged under four families, comprising : (1.) Cyat'ioplri/llida; distinguished by the absence of a columella and by the absence of a distinctly cruciform arrangement of septa; (2.) Lonsd(iltd(B, in which a distinct columella is present ; (3.) Staurida, characterized by the primary septa forming a distinct rectangular cross ; and (4.) Halliadie, with distinctly twofold arran- gement of septa. a ■ CORALS AND (^OKALFilFORM TYPES. 48 Fam 1. Cyathnphi/lltdrr. Group A.— Tesselalt : Compound vesioiilo-stellatc Ci/atlio/th!/lli(l(C composed of closely uuitod corallites, forming mosaic-liko, tesselatod or asteroidal groups. Ci/athogonium, E. J. C. ( = tesselati'd forms of Ci/ulliojilii/llitm ; also Str- abodes and Acervularia), Sil., Dev., Carb. HeHos;onium, E. J. C. ( = tesselated forms of Helv-pfiyl/um), Sil., Dev. Phillipsaslrcsa, E. & H. (including Puchyphijlium), Dev., Carb. Group B.—Aritndinacei : Vesiculo-stellato CyathophijUidfC, composed of roed-liki- or tubular corallites, either .simple or in partially connected groups. Cannophyllum, E. J. C ( = reed-like forms of Ci/alhophyUum), Dev., Carb. Dipliy/iJiyllum, Lonsd. (including Slylaslrea), Sil., Carb. Eridophyllum, E. k H., Sil., Dev: Group C.—Corntculati: Simple vesiculo-stellate C//«Mf#/y//«V^'' of more or less conical or horn-like form. Cyaihophylhtm, Goldf. (including Dicophylhim and Compophylhtm), Sil., Dev., Carb. Heliopliyllum (r .ig AntntliopltyUmii), Sil., Dev. Blothrophyll .il.. Dev. Chsiophyliwh, Dana, Sil, Dev., Carb. {Pycnophylltm, Linds., Sil. 0 Strephodes, McCoy, Sil., Dev., Carb. Fam. 2. Lonsdalidce. Group A. — Aggregali: Compound forms of IfOrts. Vesiculo-Stbllata : Fam. Cyathopliyllidif : i- pliyphyllnm, Eridopliyllum). Group)!, ('oniic'ilati (•■ g. C'yathopliyllum, Ile- liophylluni, Clisiopliylhim, etc.). Fam. Lonsdalid:i : (jroup 1. Aggiegali (e. g. Lonsdalia, Litliostro- tion). Group 2. Turhitiali (f. ;/. Axopliyllum, etc.) Fam. Staurida: : Group 1. 'I\mluii (i . g. Stauria). Group 2. Tuib'mnll {i.g. Onipliynia). Fam. II'dHid.i ((>. g. Ilaliia). ^ (i. Vesiculosa : Fam. ( gHiphyllkhe: Group 1. Aggngati [e. g. ("ystipliylloidrs, etc.) Group 2. O'liiicvkiti (f. ;/. Cystipliyllum). ? 7. Ol'EEClI.Al A : Fam. CuJcc'jUdx : Group 1. Amndiiiacei (c. g. Fletclieria, Rliizo- pora). Group 2. Unii-alntli {<-. g. Calceola, Rliizopliy'- lum). Group ". Tilraralvaii (c. g. Gouiopliylluni). ^ 8. Istegri-Stellata : I'am. i'ljcliiiidii: : Group 1. ^^piniffii (f. g. Acanthocydus). Group 2. Alttmati {t\ g. Palicocyclus). Groups. Siilcad (c ;/. Microcyclus, ("ami)0pliyl- lum, etc.) Fam. Fitraidx {,. g. Petraia, Polycsjelia, etc.) Fam. Cyatlioxonidx {e. g. Cyatliaxonia, Duncan- ella, Duncania.)