174 PEOF. p. MARTm DTTlfCAIf'S REVISION OF THE 



ating regularly from the centre of tlie base to the circumference, 

 and formed of granules moderately distinct. Wall regularly 

 perforate. 



Distribution. — Fossil. Cretaceous, Eocene, Miocene, Pliocene : 

 Europe and England. Tertiary : Asia. — Secent. Pacific, Philip- 

 pines, and Ke Islands. 



Subgenus Discopsammia, A^Orbigny, Note sur les Polyp, foss. 

 p. 10 (1849). 



Corallum plano-convex, with a superficial calicular fossette, a 

 rudimentary columella, and the free edges of the septa rounded 

 and slightly denticulate. 

 ■Distribution. — Fossil. Cretaceous series of Europe. 



This subgenus corresponds to the Lenticular StepJianopTiyllice of 

 Milne-Edwards and Jules Haime. 



Genus Leptopenus, Moseley, Report on ' Challenger ' Corals, 

 1879 (pub. 1881), p. 204. 



Corallum discoid, excessively thin and fragile, with the wall 

 so completely covered by perforations as to resemble lacework, 

 being built up of a network of delicate radiating and circumferen- 

 tially-directed trabeculae. Perforations placed at regular intervals 

 between the costse, and each divided into two by the septa, which 

 alternate with the costse. Septa, except the primaries, which are 

 free, coalescing successively according to order, and forming del- 

 toid figures beset with a series of long, outwardly-directed spines 

 on their free margins ; attached beneath to the transverse trabe- 

 culse, which separate frocQ one another the perforations of the 

 wall by a series of short processes, in the intervals between which 

 their lower margin is free. Columella large, spinous. Tentacles 

 knob-bearing. 



Distribution. — Recent. Sea-floor of Southern Hemisphere, deep 

 water (over 1500 fms.). South Atlantic, South Indian Ocean, and 

 ofi" Valparaiso. 



Genus Cyclobacta, BolscJie, Zeitschr. deutsch. Geol. Gesell. 



Band xviii. p. 473 (1866).. 

 This is probably identical with Fungia, and is therefore a link 

 between Micrabacia and Fxingia. I do not place the genus. 

 Distribution. — Fossil. Cretaceous : Europe. 



