26 VERRILL, SYNOPSIS OP 



some length, but very irregular in form. The cells are very 

 small and inconspicuous among the tubercles. On the exte- 

 rior the surface is but little tubercular and the cells are 

 larger, more regular and somewhat prominent with twelve 

 septa, of which six are very small. 



Gaspar Straits. Capt.. John Rodgers. 



MONTIPORA PORITIFORMIS Verrill, nov. sp. 



Corallum branched, forming clumps of round, crooked, 

 proliferous branches often digitate at the ends. Surface 

 without prominences, even, very porous. Cells regularly 

 and rather closely arranged, small, even with the surface, 

 or, occasionally, surrounded by a slight elevation, having six 

 well developed and nearly equal septa, with sometimes oth- 

 er rudimentary ones between. Coenenohyma finely echinula- 

 ted with crowded, lacerate granules. 



Height five inches ; diameter of branches .35 ; of cells .03. 



Loo Choo Islands. Dr. Wm. Stimpson. 



This species is allied to M. tortuosa and M. digitata, but 

 has larger and more crowded cells than either, with coarser 

 and more irregular branches, and the ccenenchyma is more 

 loose and porous. 



These three species would appear worthy of being sep- 

 arated generically from the typical, tuberculated species were 

 it not for the fact that even those often present, at the base 

 and on foliaceous expansions, cells which are not accompanied 

 by any tubercles or other prominences. 



MONTIPORA RIGIDA Verrill, nov. sp. 



Corallum branched, the branches strongly compressed, 

 thin at the summits, forming flattened clusters of branchlets 

 coalescent below. Cells small, situated at the bottom of 

 larger cell-like depressions formed by thin, angular elevations 

 of the coenenchyma between and around all the calicles, giv- 

 ing the surface the appearance of some madrepores with 

 short open corallites. The septa are imperfectly developed, 

 six in number, trabicular and spinose, coenenchyma firmer 



