FAMILIES AND GEISTERA OP THE MADREPOEAEIA. 79 



dichotomoiis, free soon or almost entirely so. The calices have 

 an irregular margin, and are more or less circular or subcircular, 

 and they are shallow. The columella is rudimentary, or absent. 

 The septa are numerous, and nearly equidentate. The endo- 

 thecal dissepiments are oblique and well developed. The wall is 

 naked, or may have a rudimentary epitheca, and is covered with 

 equal or subequal granular costae. Circular expansions of the 

 wall occur at different heights, and may or may not unite with 

 those of other corallites. 



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

 Europe. Secondary : Europe. Tertiary : Europe, Sind, Aus- 

 tralia ? 



Grenus PLEUEOPHXiiLiA, F. de Fromentel, Introd. a Vetude des 

 'polyp, foss. p. 140 (1858-60). 



Colony with small dichotomous or trichotomous branches. 

 CoralHtes cylindrical, multiplying fissiparously. Calices with the 

 septa arranged on the heptameral type, one of the seven large 

 septa being the most developed, and reaches the axis without 

 diminishing in thickness, and replaces a columella. The wall is 

 covered with a thick epitheca, swollen in bourrelets here and 

 there. 



JDistrilution. — Fossil. Portland Oolite: Europe. 



Grenus Dekdeocora, Duncan, Deep-Sea and Littoral Corals, 

 Proc. Zool. Sac. 1876, p. 438. 



Colony bushy, branching from all parts, frequently in one plane. 

 Branches different in length, slender. Calices terminal, round, 

 shallow or elongate when undergoing fissiparity. Columella lax 

 and trabecular. Septa denticulate, with pali before those of the 

 third cycle. Costse distinct, broader than the septa of the calicular 

 margin, and are sharply granular over the all. Wall thick. 

 Endotheca tolerably abundant. Epitheca absent. In some 

 branches the fissiparity is repeated to form short series. 



Distribution. — Recent. Atlantic, West coast of Africa. 



Grenus Dacttlosmilia, d'Orbigny^Note sur les Polyp, foss. 

 p. 6 (1849). 



The colony is dendroid, and has dichotomous corallites. The 

 columella is spongy and well developed. The septa are dentate 

 and in three or four cycles, and there are pali before all, with the 



