166 PROr. p. MAETIN DUNCASr's REVISION OF THE 



Alliances. 

 I. Leptophyllioida. 



II. MiCROSOLENOIDA. 



Groups Cyclolites and Mycetar^a. 



I. Alliance LEPTOPHYLLIOIDA. 

 Simple Plesioporitidse, turbinate, conico-cylindrical, fixed or not. Epi- 

 theca present or absent. Septa very numerous, trabeculate, perforate, 

 uniting, joined by synapticula. 



Genus Leptophyllia, Reuss. 



Subgenus Thecoseris, E. de From. 

 Subgenus Trochar^a, Etallon. 

 The genera Thecoseris and Trocharcea become subgenera; Saplarceais 

 not placed. 



Genus Leptophyllia, Reuss, Deiikschr. der Wiener AJcad. der 

 Wiss. t. vii. p. 101 (1854) ; JPratz, JPalceoniographica, p. 90 

 (1882). 



Syn. Ila^larcea, Milas. 



The corallum is simple, fixed, and pedunculated ; tie wall is 

 naked and marked with close costse, Avhich are numerous aud 

 granular. The calice is circular or subovular or elliptical in out- 

 line. The columella is absent. The septa are very numerous, 

 close, thin, often uniting, and are composed of vertical trabeculge 

 with vertical rows of perforations between them. Synapticula 

 occur in abundance, and are found high up in the interseptal 

 loculi. Dissepiments occur in the interseptal loculi. EjDitheca 

 absent. 



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



It is not possible to retain the genus Ilaplarcea, as its di- 

 Btinetion from Leptophyllia is having an epitheca, and this is not 

 generic in importance. 



Subgenus Thecoseris, (genus) JE. de Fromentel, Pal. Fran^., 

 Zooph., Terr. crU. p. 367 (1869). 



Corallum elevated and regularly turbinate. Calice concave, 

 and the fossa round. Septa thin, numerous, not exsert, often 

 anastomosing and finely denticulated, the larger usually meeting 

 in the centre of the calice and forming a false columella. Wall 

 thin, costse numerous, covered to the margin of the calice by a 

 strong folded epitheca. Synapticula feebly developed. 



