FAMILIES AND GENERA OP THE MADREPORARTA. 



21 



The form described by Mr. Tennison Woods may then be thus 

 described generically : — 



Q-enus Trematotrochtts, T. Woods, amended. 



Corallum simple, regularly conical, elongated, free. Calice 

 circular, with a well-developed margin. Columella none. Septa 

 few, short ; those which are large and equal extend close to the 

 axial space, and form a tube-like space. A cycle of rudimentary 

 septa corresponds to costse which are nearly as large as those 

 of the other septa. Paliform nodules on the primary septa. 

 Intercostal spaces regularly fenestrated? Neither endotheca 

 nor synapticula exist. 



Distribution. — Fossil. Miocene or Cainozoic : Australia. 



V. AUiance TROCHOOYATHOIDA. 



Simple Turbinolidae, with wall, costae with or without epitheca. Pali 

 in one or several crowns, or absent. Columella fasciculate. Shape 

 variable. 



Genus Trochocyathus, Ed. & H. 



Subgenus Tropidocyathus, Ed. & H. 

 Subgenus Thecocyathus, Ed. & H. 

 Subgenus Blanfordia, Duncan. 

 Genus Deltocyathus, Ed. & H. 

 Genus Odontocyathus, Moseley. 

 Genus Leptocyathus, Ed. & H. 

 Genus Paracyathus, Ed. & H. 

 Genus Heterocyathus, Ed. & H. 

 Genus Caryophyllia, Lmk. 



Subgenus Acanthocyathus, Ed. & H. 

 Genus Stenocyathus, Pourtales. 

 Genus Ceratotrochus, Ed. & H. 

 Genera absorbed : — 



Aplocyathus, d'Orb. ; Stephanocyathus, Seguenza; 

 Platycyathus, E. de From. ; Bathycyathus, Ed. 

 & H. ; DuNOCYATHUs, T. Woods ; Blastocyathus, 

 Reuss; CoNOTROCHUS, Seguenza; Epitrochus, E. de 

 From. ; Pleurocyathus, Moseley, Keferstein, and 

 E. de Fromentel ; Crispatotrochus, T. Woods. 

 The genera Tropidocyathus, Ed. & H., Thecocyathus, Ed. & H., 

 Blanfordia, Dune, and Acanthocyathus, Ed. & H., become subgenera. 



The Trochocyathoid alliance is a large one, and contains genera 

 which have persisted from the age of the Lias to the present time ; 



