246 A. E. Verrill — Corals of the Genus Acropora. 



that lias not yet received a distinctive name, hence I propose to call 

 it A. secaloides. 



It is a flat-topped corymbose clump, about 18x15 inches across 

 (450x375'°'"), and five inches (125'°"^) thick. It arises from a stout, 

 short, pedicellate base. The nearly horizontal primary branches 

 coalesce into a nearly solid plate subcentrally, but farther out there 

 are many irregular openings, and numerous flattened, obtuse, 

 appressed brauchlets, with only a few small, immersed calicles, the 

 surface in general appearing rather smooth, as if covered with 

 plaster of Paris. 



The upper side is covered with nearly upright,, moderately stout 

 dichotomous branches, mostly 12-18'"'° in diameter at base. Those 

 of the central parts are 75 to 100""° long. They may fork two or 

 three times ; most often they divide near the base into two or three 

 ascending branches, and these again divide into 2 to 8 terminal 

 branchlets, 25 to 50'°'" long. Some of them may be proliferous 

 near the tip ; they are mostly 8 to 10""° in diameter, little tapered, 

 obtuse. 



The axial corallites are of moderate size, 2.5-3.5"°"', usually about 

 3mm j^ diameter, and 1-2°"° exsert, with the walls rather thick, com- 

 pact, and finely, evenly echinulate-granulate, not at all costulate ; 

 calicle small, with 12 unequal septa. 



The larger radial corallites are short, divergent, with ver}' thick, 

 prominent, rounded outer lip, not appressed ; inner lip usually 

 wholly adnate ; calicles, rather small, .07-.08""", conspicuously stel- 

 late, opening upward, little visible in a side view ; primary septa 

 well developed, secondaries narrower, but very distinct. Walls 

 thick, compact, very evenly and finely echinulate-granulate, like the 

 coenenchyma. 



Between the larger radial corallites there are many smaller ones, 

 often verruciform, with short lips, and some wholly immersed. 

 On the proximal third of the branches most of the calicles are 

 immersed, but stellate with 12 septa. Cffiuenchyma rather compact, 

 everywhere evenly echinulate-granulate. 



Singapore, U. S. Expl. Exped., No. 2033, Yale Mus. 



Probably this species has been included under A. secede by several 

 writers. Indeed, it is quite probable that Studer himself so included 

 it, for he refers to specimens of the latter from Singapore, but he 

 did not describe them. It does not appear to agree with A. secede 

 (Brook), non Stud., which has more appressed corallites, but it may 

 be that it varies in this i-espect. 



