244 A. JE. Verritt — Corals of the Genus Acropora. 



Acropora secale (Stud.) Ver. See p. 21*. 



Madrepora plantaginea Dana, Zooph., p. 459. 1846 (non Lam.). 



Madrepora secale Studer, Reise Corv. Gazelle. Monatsb. Kongl. Preuss. 



Akad. Wissens., Berlin, 1879, p. 530 (non Brook, p. 88, 1889). 

 Madrepora Ceylonica Ortmann+ilf. remota Ort. + M. valida Ort. + .1/. srml,- 



Ort., Zool. Jehr., 1889, iv, pp. 506, 510, pi. xiii. fig. 6; pi. xli, fig. 3. 

 M. Ceylonica Brook, op. cit., p. 162. 



Plate XXXVI. Figures 14, 14a. Plate XXXVI B. Figures 5, 5a. 



The large specimen from Ceylon, described by Dana, which is 

 distinct from his Singapore specimens, is in the Yale Museum (coll. 

 G. H. Apthorp). This is a crescent-shaped corymbose clump, 

 attached by a large, one-sided pedicel. It is about 2 feet long and 

 1 foot broad, with the upper surface a little convex, the length of 

 the upright branches decreasing from 75-85 mm in the middle to 25 

 to 40 mm near the border, while the under side is inclined upward. 

 The main branches are completely coalesced, so that the under side 

 is a nearly even, thick plate, without any projections and with 

 scarcely any openings, except close to the margin, where the 

 branches are reticulately joined ; the immersed calicles of the under 

 side are scattered, small, six-rayed. 



The upright branches of the upper side are rather stout (mostly 

 10 to IS 1 " 111 ), obtuse, somewhat angular, sparingly proliferous, except 

 the marginal ones. They are rather close, mostly separated by 

 intervals of 12 to 20 mm . 



The axial corallites are rather thick and swollen, rounded, little 

 exsert, with a small calicle and thick, porous walls ; diameter, about 

 3-3. 5 mm ; calicle, about l ,nm . The calicle has 12 thin, narrow, sub- 

 equal septa ; wall closely and finely echino-granulate, in series. 



The radial corallites are very unequal in size and form. The 

 larger ones, which are mostly on the distal part of the branches, 

 and within 25-35 mm of the tip, are large, tubular, a little tapered, 

 with thick walls, rounded at tip, and with a small terminal calicle. 

 Many of these have a few small, radial calicles on their basal por- 

 tion, and are then like incipient branches. They are 3-6 mm exsert ; 

 diameter about 2.5-3 mm . 



Between these, with some nearly or quite immersed calicles, are 

 also many short (l-2.5 mm ), thick, ascending or appressed, tabular 

 corallites, with the outer lip thick, rounded, and often a little in- 

 curved, and the calicle oblique and slightly elliptical ; the inner lip is 

 short and thin, or often abortive. Wall densely and finely gran- 

 ulated, with sharp granules arranged in costal stria-. 



