212 A. JEJ. Verrill — Corals of the Genus Acropora. 



Though some of the ten " subgenera " of Brook are useful divi- 

 sions, for diagnostic purposes, others are not of any practical value, 

 and often serve more to mislead than to help the student. This 

 remark applies particularly to those based on slight differences in 

 the mode of growth or branching, and on small variations in the size 

 or prominence of the terminal or axial corallites. One part of a 

 single specimen will often go in one such " subgenus," while another 

 part Avill go in another. 



The forms of the radial corallites ; the texture of the coenenchyma; 

 and the presence or absence of distinct costs 1 , would give more con- 

 stant characters for the differentiation of sections of the genus. 



For this reason much enlarged photographic figures of the calicles 

 and coenenchyma are of the greatest value in illustrating species of 

 this genus. Drawings seldom give the complex texture satisfac- 

 torily. Young specimens of all the profusely branched species appear- 

 totally unlike the mature forms, and are, therefore, apt to be errone- 

 ously determined. 



List of Species of Acropora examined. 



I have arranged the species alphabetically, for greater convenience 

 of reference. 



An asterisk prefixed, indicates that the species is in the Museum of 

 Yale University. 



Authorities for names and localities are often much abbreviated : B.= Brook ; 

 D.=Dana; E. and H. =Edw. and Haime ; Kl. = Klunzinger ; Q. =Quelch; B. = 

 Eehberg; St. = Studer; V.= Verrill. 



*Acropora abrotanoides (Lam., non Dana, see polymorpha). 



Brook, op. cit., p. 56, 1893. 



Singapore (B.); Polynesia; Tahiti (B.); Great Barrier Reef (B.). 



*A. acervata (Dana). Brook, p. 147. See notes, below. 



Singapore (D., Y.). 

 *A. acideus (Dana). Brook, p. 104. 



Fiji (D.) ; Philippines ? (Quelch). 



*A. acuminata (Ver.) Brook, p. 38. See notes, below. 



Kingsniills Is. (Ver.). 



*A. alliomorpha (Brook, p. 87). Singapore (B.). 



*A. amblyclados (Brook, p. 140). 



Singapore, Indian O., and Australia (B.). 



*A. appressa (Ehr., D., not appersa, as in Edw. and II.) Brook, p. 



85. See notes, below. 



Singapore and Ceylon (D., V.). Loc. of type unknown. 



