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



Acropora neglecta Ver., sp. nov. 



Plate XXXVI. Figure 21. Plate XXXVI E. Figure 7. 



Plate XXXVI F. Figure 5. 



The other species, mixed with the last, which I have been unable 

 to identify, is represented only by a single terminal branch, 13 mm 

 in diameter, with a few short, divaricate branchlets, three arising 

 at one point in one case. It was evidently arborescently branched. 



Axial corallites about 2.5 mm in diameter, and 3 mm exsert, with 

 strongly costulate wall, and 12 very distinct subequal septa, the 

 directives wider. 



Radial corallites are tapered, tubular, or conoidal, ascending, not 

 compressed, obliquely truncate, with the round stellate calicle looking 

 upward and somewhat outward ; outer lip a little prominent, not 

 much thickened, narrowed, and incurved; inner lip thin, usually free 

 for a short distance, but often entirely adnate. Outer wall strongly 

 costulate, with the costula3 rather coarsely echinulate, and with small 

 pores in rows between the costuhe. 



Septa 12, unequal, but all narrow, the directives a little wider. 

 There are but few small calicles between the larger, and none 

 immersed. 



The larger corallites are openly arranged, much fewer than in poly- 

 morpha, and very different in the conoidal form and strongly costu- 

 late exterior. The coenenchyma is irregularly and strongly pitted 

 and roughly echinulate. in series. This is a true Eumadrepora 

 (Brook). 



Probably this specimen was from Singapore, or that region. U. S. 

 Expl. Exped., 1846. No. 6126, Yale Mus. 



■ 



Acropora pumila Ver. 



Madrepora pumila Verrill, Coinm. Essex Inst., v, p. 23, 1866. Brook, p. 166. 



Plate XXXVI. Figure 5. Plate XXXVI A. Figure 5. 



Plate XXXVI D. Figure 9. 



In addition to the original description, which is pretty complete, 

 the following points are noted. The calicles, both axial and radial, 

 are unusually small, mostly not over 0.5""", and some on the lower 

 branchlets are immersed and still smaller, but the immersed calicles 

 are scattered and inconspicuous. On the lower branchlets the axial 

 corallites are often so thickened that the calicle becomes very small, 

 or almost obsolete. Some of the calicles, both radial and axial, have 

 12 septa ; the primaries are all rather narrow and subequal ; the 

 secondaries very narrow. 



