162 A. E. Verrill — Bernntdlan a)ul West Indian Reef Corals. 



This coral is much heavier and more solid than P. astreoides. Its 

 calicles are larger and deeper, and separated by thicker, more prom- 

 inent, and more solid walls. The details of the calicles are also 

 different, as best shown by enlarged photographic figures. 



The 12 septa are well developed and wider than usual. The colu- 

 mella is large, nearly solid, and usually has a central tubercle. Pali 

 are rudimentary or lacking. 



That abnormal or imperfectly developed calicles of P. astreoides 

 or P. clavaria (auth.) may resemble normal calicles of this or other 

 species, is not sufficient proof that they are identical, as Mr. Gregory 

 and Mr. Vaughan seem to think. 



If we should use this as a crucial test, then all known species of 

 Porites could be reunited into one polymorphic species, for all sorts 

 of variations of this kind can be found in every species of the genus. 

 The same is true of many other genera of corals, e. g. Madrepora-=. 

 Acropora V., where the existence of imperfect or unusually formed 

 calicles is a feature found in most of the 200 species. 



The only reasonable way to group such corals into true species is 

 to compare calicles that are normally and naturally developed, and 

 those that are fully grown. Starved specimens or calicles, and those 

 that are dwarfed or abnormal from other unfavorable conditions, are 

 very liable to mislead, in this and many other genera, and should not 

 be made too much of. 



So the average size of well-developed calicles is generally charac- 

 teristic of species, even though the dwarf calicles of one might not 

 exceed the average calicles of another. The same rule will apply to 

 all other characters, for all the characters are variable. 



According to Mr. R. Rathbun, this species is common on the coast 

 of Brazil, from Parahyba do Norte to the Abrolhos Reefs, and is 

 abundant at Pernambuco. But perhaps part of his specimens were 

 P. astreoides, variety. See p. 161. The type was from the Abrolhos 

 Reefs,— coll. C. F. Hartt. No. 4539. 



Porites Branneri Eathbim. 



Porites Branneri Eath., Catal. Porites, Proc. U. S. Nat. Mus.. vol. x, p. 355, 

 pi. xix, fig. 3, 1887. Vauglian, op. cit., p. 77, 1901. 



Plate XXXI. Figures 6, 6«. 

 Two Brazilian specimens in the Yale Museum agree well with Mr. 

 Rathbun's description. They are regularly and evenly rounded, 

 very porous masses, formed by a thick encrustation over other species 



