SUBCLASS II 



HEXACOEALLA 



97 



Firi. 138. 



Monti! vaUia riiryuiihyllata (Lanix.)- 

 Caen, Calvados. Natural size. 



Great Oolite ; 



readily becoming detached. Common in Triassic and Jurassic ; somewhat rare 

 in Cretaceous and Tertiary. The genus should probably be made to include 

 various species which have been referred to Epismilia From., and the so-called 

 OpjJdismilia Duncan. 



/3. Simple corolla or composite colonies 

 multiplying Inj calicinal or marginal gem- 

 mation. 



Stylopliyllum Keuss. Corallum simple, 

 either with or without calicinal or 

 marginal gemmation, or forming massive 

 colonies. vSepta stout, but only in- 

 feriorly complete, terminating above in 



strong vertical spines. Dissepiments vesicular ; wall covered with epitheca. 

 Alpine Trias. 



Stylophyllopsis Freeh. Simple or imperfectly branching. Septa terminating 

 near the centre in detached vertical spines. Alpine Trias. 



y. Bushy colonies multiplying by lateral gemmation. 



Cladocora Ehrbg. Corallum composed of long 

 ' cylindrical branches, free on all sides. Calice circular ; 

 septa well developed ; columella papillous ; cycle of 

 pali present. Jurassic to Recent. 



Sfylocora Reuss (Fig. 139). Branches cylindrical; 



septa stout, those of the first cycle with columnar 



PiQ i39_ thickenings or inner edges ; columella styliform. 



styhcom e.ri.iis Reuss. Mio- Cretaceous and Mioceue. 



c::;L^^fn!i^'S^. t: Plenrocora E. and H. Cretaceous. Goniocora E. 



Calice enlarged (after Reuss). and H. TriaSsic and JuraSsic. 



8. Composite coraUifes multiplying by basal gemmation ; buds arising from stolons 



or basal expansions. 



Bhizangia E. and H. (Fig. 140). Corallites united by short, sub-cylindrical 



Rhisantjiamichelini Reuss. Middle 

 Cretaceous ; Gosau Valley, Austria. 

 Natural size (after Reuss). 



Fio. 141. 



Claikmgia conferta Reuss. Miocene ; Bischofs- 

 wart, Moravia, a, Corallum, natural size ; b, 

 Calice enlarged (after Reuss). 



stolons. Calices shallow, circular; columella papillous. Cretaceous and Tertiary. 

 Latusastrea d'Orbigny. Corallites arising from common basal expansion, 

 short and strongly inclined to one side, so that the calices acquire a semi- 

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