18 



PROF. P. M. DUNCAN ON THE MADREPORARIA 



and others nearer the ealicular margins of the corallites. Coral- 

 lites turbinate, compressed. Calices elliptical, often much com- 

 pressed, longer than broad, with a moderately stout margin. 

 Septa slightly exsert and projecting but slightly from the wall 

 towards the axis of the calice, thin, imperforate except close to 

 the wall, and with plain edges ; the smaller with ragged edges 

 and often with projections on them near the columella. There 

 are four complete cycles, and part of a fifth may exist. In the 

 large calices the fifth is nearly complete and the primaries and 

 secondaries are equal ; the tertiaries are slender and do not 

 project much from the wall, but they become large near the 

 columella on account of the junction of the higher orders with 

 them. The septa of the fourth and fifth orders reach halfway 

 down the corallite and join the tertiaries, and the small cribriform 

 septa of the fifth cycle join the fourth and fifth orders not far 

 from the calice. Or this last junction may not take place. 

 Columella deep, small, elongate, formed of lax trabecule, and 

 these join the principal septa. Wall stout, cribriform, perforated 

 very regularly. Costse variable, usually subequal, minutely 

 granular, projecting slightly. The long and short axes of the 

 margin of the calices are on different planes. 



Height 38 millim. ; breadth of free surface 20-25 millim., length 

 of the free surface 35-45 millim. ; length of calices 8-15 millim., 

 breadth 8-12 millim. ; depth of large calices 8-15 millim. 

 Locality, Mergui Archipelago. 



Subgenus C(Enopsammia, (gen.) Ed. H. y Dune. Bevis. p. 178. 



Dendrophtllia (Ccenopsammia) affinis, sp. nov. (Plate I. 

 figs. 29, 30.) 



The colony is low, more or less hemispherical, and encrusts. 

 Corallites project slightly above the lax, highly porous cnenen- 

 chyma. Calices circular in outline, as deep as they are broad. 

 Septa with three cycles, often incomplete, and rarely an order of 

 the fourth ; primaries are a little exsert, imperforate except 

 near the wall, slightly granular, and larger than the secondaries ; 

 both join the columella. The smaller tertiaries may bend 

 towards and join the secondaries, but the opposite condition is 

 quite at frequent, and the Eupsammine condition is often not 

 Men. Columella deeplj seated, small, and composed of two or 

 three trabecule, or larger and of many trabeeula). Costa? 



