FAMILIES AND aENER^ OF THE MADllEPORARIA. 



191 



polygonal, numerous, minute, irregular. Septa a series of 

 needle-shaped points. Wall of corallites thickly studded with 

 short, stout, and very conical points, swollen at the base, and 

 23ointing towards the interior of the fossa. A common epitheca 

 in very thick folds. Gremi nation intracalicular. 

 Distribution. — Recent. Pacific. 



The Kev. T. Woods gives a delineation of the species; and 

 there is no intermediate cuenenchyma shown between the calices. 



M. de Fromentel, op. cit. p. 256, places the genus Pleuro- 

 dictyum, Goldfuss, in the group Perforata, which includes Porites. 

 This genus finds no place amongst the Madreporaria Perforata, 

 as it is founded on a cast of a species of the genus Michelinia, 

 a Palaeozoic tabulate form which in all probability belonged to 

 the Alcyonaria. 



M. de Fromentel* places the genus Holarcea, which was 

 founded by Milne-Edwards and Jules Haime to receive Alveo- 

 lites parisiensis, Micbelin, amongst the Perforata in the neigh- 

 bourhood of Porites. The condition of the specimens on which 

 the above-named species was established is very defective. Milne- 

 Edwards and Jules Haime, in 1860, in their ' Hist. Nat. des 

 CoralL' vol. iii. p. 244, place Holarcea as a synonym of Axopora, a 

 genus with tabuisB, and certainly not one of the Madre]_3oraria, 

 but an Alcyonarian. Holarcea is therefore no longer a genus. 



The genus Coenostroma, "Winchell, is probably an ally of Stro- 

 7natopora, and not a coral. 



II. Alliance MONTIPOROIDA. 



Poritidse with a more or less abundant spongy eoenenchyma. 



Genus Montipora, Quoy & Gaira. 

 Genus Anacropora, Ridley. 



Genus Montipora, Quoy et Gaimard, Voy. ^Astrolabe,' Zooph. 

 p. 247 (1833); Verrill, Notes on Badiata, Revision of Corals 

 of West Coast of America {lSQS-70), p. 502. 

 Colony various in form, glomerate, massive, incrusting, folia- 

 ceous, lobate or branching. Coenenchyma abundant, porous, or 

 spongy, usually echinulate at the surface, and often rising into 

 ridges, papilliform eminences, and crests between the corallites ; 



* ' Introd. a I'Etude des Polyp, foss.,' Paris, 1858-60. 



