FAMILIES AND GENEEA OF THE MADREPOBAKIA. 23 



Subgenus Blajstpobdia, (genus) Duncan, Fossil Corals and 

 Alcyonaria of Sind, Fal. Indica, Sect. xiv. pt. 2, p. 73 (1880). 



Corallum cyclolitoid or nummiform in shape, with a flat base. 

 Calice open, axial space shallow, and columella deep and small. 

 Septa numerous, close. Pali before all the septa except those of 

 the last order, small ; union of the septa very usual, on both 

 sides of a long primary. Epitheca pellicular, binding the costse 

 to the discoid base. 



Distribution. — Fossil. Eocene : Sind, Asia. 



This subgenus includes a remarkable form which commences 

 upon a Numraulite, and the epitheca is very pronounced, 



Q-enus Deltoctathtts, Milne-Edwards ^ Jules Saime, Hist, 

 Nat. des Corall. vol. ii. p. 56 (1857) . 



Corallum simple, discoid or cup-shaped, free, and without trace 

 of former adhesion ; calice subplane ; columella fasciculate. Pali 

 well developed, exsert, unequal, before the cycle of septa except 

 the last, arranged in chevrons or deltas. Septa usually exsert 

 except the last cycle. Costse exceedingly variable in their deve- 

 lopment, especially the primaries spined or not. 



DistribiUion. — Fossil. Miocene, Pliocene : Europe, Australia? — 

 Becent. Caribbean Sea, N., E., and S. Atlantic, Corean Sea, Pacific. 



G-enus Odontocyathus, Moseley, Beport on Corals ^Challenger' 

 Fxped. p. 148 (1881). 

 Corallum deep saucer- shaped, with straight sloping sides and 

 a broad flat base, free, but with a scar of former adhesion. 

 Columella fasciculate. Pali in three crowns. The broad base is 

 composed of fused radiating tuberculate spines, which project 

 like the spokes of a wheel all round the base of the wall. 

 Distrihition. — Becent. West Indies. 



Grenus Leptoctathus, Milne-Edwards 8f Jules Uaime, Hist. 

 Nat. des Corall. vol. ii. p. 50 (1857). 



Syn. Ecmesus, Phil. 



Corallum simple, very short, subdiscoid, free, and without trace 

 of former adhesion. Wall with simple costae. Calice circular 

 and excavated in the centre. Columella papillary. Septa exsert ; 

 and there are denticulate pali before all the septa. 



Distribution. — ^omZ. Eocene : England, Europe, India? — 

 Becent. Caribbean Sea, Azores, Josephine Bank ? 



