105 



S. HETEROCYATHUS AEQUICOSTATUS (Ed. and H.). 



(PI. III., figs. 1-43-) 



H. aequicostatus, Ed. and H., Cor. II., p. 51 (1857). 



H. phillipinensis, Semper, Zeit. f. wiss. ZooL, XXIL, p. 254 

 (1872). 



//. parasiticus, Semper, Zeit. f. wiss. ZooL, XXIL, p. 255 (1872). 

 (1872). 



H. pulchellus, Rehberg, Abh. Ver. Hamb., XII., p. 8 (1892). 

 H. oblongatus, Rehberg, Abh. Ver. Hamb., XII., p. 9 (1892). 



The collection contains upwards of 900 specimens of this 

 species, made up as follows : — 



The collection contains so large a number of specimens that 

 I have been enabled to make a study of its variation. Com- 

 paring the specimens from each locality together, and with the 

 collections from different localities in the British Museum, it 

 was clear that each locality had a size-mode of its own. This 

 was apparently due partially to the particular species of shell on 

 which the coral had affixed itself in each locality, but mainly 

 to the environment, tropical forms, for instance, being usually 

 larger and coarser than Cape forms. At the same time, the 

 characters of the costae, septa, theca, pali, and columella were 

 not affected; and plenty of intermediates existed, so that all 

 clearly belonged to a single species. 



