Ven-ill, JSfotes on Hadiata. 5 1 9 



as a distinct family, which has, perhaps, closer relations with Madre- 

 poracea. The genus Seriatopora, has been united with certain genera 

 of fossil corals to constitute a distinct family, Seriatoporidce, hut it 

 would appear to be more in accordance with their true affinities to 

 unite Seriatopora and the allied genera with the Pocilliporidm. The 

 living polyps are unknown, however, and might show other relations. 

 The ThecidcB E. and H., and especially Golumnaria, are evidently 

 very closely allied to PoctlUpora and, ought, perhaps, to be united in 

 the same family. 



The association by Edwards and Haime, and others, of the MllUpo- 

 ridce with PocUUporid(t^ and allied forms, under the name, Tahidata, 

 was particularly unfortunate, since they have no relations whatever, 

 and indeed there is no resemblance except in the fact that in certain 

 genera of both groups there are transverse septa, — an artificial char 

 acter of comparatively little importance, which also occurs in the 

 Astrceidiv. [Coelastrcea) and sometimes even in the Eupsaiumklce 

 (Astrceopsammia). Prof. Agassiz has shown that Milleponi belongs 

 to the Hydroidea, and holding the opinion that Pocillipora and other 

 talnilated corals were allied to Millepora he consequently united all 

 the Tabidata of Edwards and Haime to the Hydroidea, thus removing 

 them from the class of polyps. This view is no longer tenable, since 

 the genus Pocillipora has animals identical in structure with the most 

 typical genera of true polyps. Even were the animals of PocilUpora 

 unknown, the examination of such species as P. elongata Dana, P. 

 plicatd Dana, P. stellata Verrill, and others, in which there are twelve 

 well developed septa, having the same essential characters as those of 

 OculinidcB and Stylophoridce, would be sufficient to convince us that 

 the genus could not i:)Ossibly belong to the Hydroidea, unless that 

 group is to be so modified as to lose the principal characters by which 

 it is separated from the class of polyps. The al)sence of radiating 

 lamellfe, such as would be required to secrete the radiating septa of 

 Pocillipora, Golumnaria, and some Pavositidce is one of the principal 

 class characters by which Acalephs are separated from Polyps, and is 

 a constant feature of acalephs ; the presence of such lamellae is equally 

 constant and characteristic of true polyps. 



Pocillipora Lamarck. 



Focillopora (pars) Lamarck, Hist. anim. sans vert, ii, p. 273 ; 2nd ed., ii, p. 144. 

 PociUopora Dana, Zoophytes, p. 523; Edw. and Haime, Corall., iii, p. 301. 



The coralla consist of clusters of branches or lobes, varying in the 

 difierent species from very slender, much divided branchlets to stout, 

 Trans. Conxecticut Acad., Vol. I. 65 Nov., 1870. 



