POLYPS AND CORALS. 83 



MADREPORAIIIA. 



Madreporidje. 

 Madrepora microphthalma Verrill, sp. nov. 



Corallum numerously divided, somewhat arborescent, 

 the branches subpiuuate, spreading mostly in one plane, 

 proliferous towards the ends, covered with small, unequal, 

 tubular corallites, which have very small, circular, regu- 

 larly stellate cells, surrounded by thickened borders. 



The main trunk gives off branches subpinnately on two 

 sides, which diverge rapidly and are usually less than a 

 quarter of an inch apart. A few smaller branches also 

 rise from the front and back sides of the trunk and main 

 branches, which do not conform to the common plane of 

 the other branches ; the secondary branches and branch- 

 lets arise somewhat irregularly from the larger branches, 

 varying from .12 to an inch or more apart below, but 

 becoming crowded and strongly divergent near the ends. 

 The l)i-aiiches and branchlets taper rapidly to the tips, 

 which are subacute and terminated by a small, slightly 

 prolonged terminal corallite, of quite porous but firm text- 

 ure, rounded at tip and perforated by a very small cell, 

 which is regularly stellate with six primary septa that 

 meet at the centre and other rudimentary septa of the 

 second cycle between them. Lateral corallites very un- 

 equal in size and elevation, diverging at an angle of 

 about 45°, tubular, somewhat tapering, truncated a little 

 obliquely at summit and rounded, the border of the cell 

 considerably thickened, especially on the outside, the text- 

 ure firm but very porous and spongiform, the surface 

 evenly echinulate, not costate. The cells are very small, 

 regularly stellate, with six, well-developed, equal septa, 

 which nearly meet at the centre. Coenenchyma firm, 

 finely echinulate. 



Height 4.25 inches; breadth 6 ; diameter of larger 

 branches .45; of terminal branchlets .25 to .30; length 

 of the latter .50 to .75 ; length of terminal corallites .10 : 

 diameter .08 to .10 ; diameter of cell .02 ; length of lat- 

 eral corallites .02 to .15, the average about .10; diame- 



