A. E. Verrill — Corals of the Genus Acropora. 233 



None of these characters apply to my original type, which is in 

 the Yale Museum (No. 774). This is a very much branched, small, 

 arborescent coral, with the branches small (larger ones about 10 mm ), 

 strongly divaricate, and very proliferous, especially distally. Many 

 of the smaller branchlets stand nearly at right angles to the branches ; 

 others at 45° or less. 



The axial corallites are small (1.75 to 2 mm ), not swollen, a little 

 exsert, slightly tapered, with the wall porous and finely echinulate, 

 rarely echino-costulate. 



The radial corallites are very unequal in size and form, but all are 

 small. The larger ones (1.5-2 mm ) are nearly regularly tubular, a 

 little tapered distally, obtuse at the end (about 3 mm long), with the 

 calicle small and only slightly, if at all, oblique, and about 0.5 to 

 0.6 mm broad, with thickened walls. The six septa nearly meet in the 

 center ; rudimentary ones of the second cycle are often present, but 

 minute. These larger corallites mostly diverge at an angle of 45° 

 or more, except distally. 



Between the larger ones are many smaller subcorneal or verruci- 

 form corallites, standing at various angles, with the terminal calicles 

 only 0.3 to 0.4 mm in diameter, while others, like small, rounded 

 verrucse, have calicles of only 0.2 mm diameter, but yet show six septa. 



The corallites and coenenchyma are densely covered with minute 

 sharp granules, and show but few pores. 



The type of A. microphthalma was from the Loo Choo Islands. 



The specimens described by Brook were from Korea, Torres St., 

 and Ramesvaren. They may, perhaps, belong to A. parvistetta 

 (Ver., 1864). 



Acropora nobilis (Dana) Ver. See p. 217. 



Madrepora nobilis Dana, Zooph., p. 481, pi. vi, fig. 3, 1846, x M. secunda, 

 var., p. 481, pi. xi, fig. 4. Verrill, Bull. Mus. Coinp. Zool., i, p. 40, 1864. 



A good Ceylon specimen ("No. 454) of this species, which was 

 used by Dana in his description, is in the Yale Museum, and also a 

 branch of his East Indian (Singapore) type. Also, one of his types 

 of M. secunda, from Singapore (No. 2014). 



In addition to these, there are numerous good specimens of this 

 species from Singapore (coll. Capt. W. H. A. Putnam and others). I 

 have also seen large series in other museums. 



The Ceylon specimen is a low clump of short, stout branches, up 

 to 25-30 mm in diameter, arising from a large basal mass. The 

 branches divide rapidly and irregularly, so that the undivided termi- 



