168 



PEOF. P. MAETm Duncan's kevision oe the 



rudimentary or absent. Septa very numerous, close, unequal, 

 often uniting, denticulate where free, trabeculate in construction, 

 with regular nodules, partly solid and often perforate, then 

 forming a latticew^ork. Synapticula feebly developed, or elon- 

 gate and visible. Dissepiments exist. 



Distribution. — Fossil. Jurassic, Cretaceous : Europe, India. 



II. Alliance MICRCSOLENOIDA. 

 Colonial Plesioporitidse, polymorphous, massive, dendroid, lobed or sub- 

 plane. A wall often present, with costse. Septa trabeculate and perforate. 

 Synapticula present. 



Genus Microsolena, Lamour. 



Genus Polyphylloseris, E. de From. 



Genus Thamnar^a, Etallon. 



Genus DiPLAR^A, Milas. 



Genus Disar^a, E. de From. 



Genus Dimorphar^ea, E. de From. 



Genus LATiMiEANDRARiEA, E. de From. 



Genus Mkandroseris, Rousseau. 

 The genera Dendrar^a, d'Orb., Actinar^a, d'Orb., Dimorpho- 

 SERis, Duncan, and Meandrar^a, Etallon, are absorbed. 



Genus Miceosolena, Lamoiironx, JExp. Metliod. des genres des 

 Polijp. p. G5 (1821) ; amended. 



Syn. Dendrarcea^ d'Orb. ; Actinarcea, d'Orb. 



Colony massive, polymorphous, mamiiliform, conical, with a 

 broad base, nearly spherical, turbinate and pedunculate, and 

 lobed, gibbous, lamelliforni, or digitiform and subramose. Basal 

 wall with delicate costae covered with a strong epitheca. Calices 

 shallow, close or distant without order. Septo-costse straight or 

 curved, delicate, close, confluent, in groups or not, minutely 

 pointed with small spinules above, and formed by vertical tra- 

 beculse swollen regularly and forming a regular latticework of 

 perforations. Columella very small or absent. Synapticula 

 abundant, small. No calicular walls. 



Distribution. — Fossil. Jurassic : England, Europe. Trias : 

 ? Europe. 



Genus Poltphtlloseeis, de Fromentel, Fol. Foss. de Vetage 

 Neocomien, p. 67 (1857). 



Colony massive and convex, Corallites united by a costal 



