4 MADREPORAEIA. 



hardly any alteratiou. The genus contains the same two species, with, however, another 

 shuffle of the specific names, viz. Ex. infwndibulum and JEx. cinerascens. 



In 1830, De Blainville* rearranged the Stony Corals, and, recognising the fact that 

 Lamarck had included in his Exiolanaria forms which were generically distinct, he rejected the 

 name " ^>7>/rt»«na " as being too indefinite, preferring Gcmmipora — in reference to the pro- 

 truding bud-like calicles. He selected the two true Turbinarians, viz. Explanaria crater and 

 Ex. mesentcrina, once more shuffling the specific names, and united with them the Madrcpora 

 peltata, of Esper and his own Gcmmipora fungiformis. These together formed a di\'ision of a 

 new genus, Gcmmipora. The division is " explaniform, and with cells only on one side," in 

 contrast to two other extant divisions : — 



(1) Arborescent : with cells on all sides, containing one species, G. ahrotonoidea, which I 

 have been unable to trace further, unless it be identical with the Madrejmra ahrotonoides, in 

 which case he classified the same coral under two different heads (' Manuel d'Actinologie,' 

 p. 387, under Gcmmipora ; and p. 390, under Madrcpora). 



(2) Encrusting : founded on Lamarck's Astrcea ptalifcra, which became Gemniipora 

 palifera, and persists as TurUnaria p)cdifcra, M.-E. and H.f 



Of this arrangement, G. crater, G. mesentcrina, G. pcltata, G. palifera and (?) G. fungi- 

 formis, persist under the changed generic name. 



It is worth noting that Blainville completely ignores Oken's TurUnaria. This is the 

 more remarkable because the type of his own species, G. fungiformis, which was a small 

 stalked disc, might have reminded him of Oken's general description of his Turbinarians. 

 Perhaps, as was probably the case with Lamarck, having larger specimens to deal with, 

 he thought Oken's description too fanciful. He clearly never discovered that Oken's genus 

 TurUnaria described the young stages of his own genus Gcmmijim^a. 



With regard to Blainville's principle of classification, he (p. 332) claims to base it on 

 the character of the animals themselves, taken together with their coralla. Owing, however, 

 to the imperfection of our knowledge of the animals, this resolves itself practically into a 

 comparison of the cells, as apart from the form of the corallum, or the distribution of the 

 polyps on its surface. Hence the name Gemmip)ora, % which called attention to the bud-like 

 cells, and was therefore thought preferable to Lamarck's Explanaria, which referred chiefly to 

 the form of the corallum. 



In 1834, Ehrenberg published his classical work on the coral-animals of the Eed Sea. § 



* Diet. d. Sci. Nat., Ix. pp. 352-3 ; repeated (1834) in his 'Manuel,' p. 387. 



f In addition, Blainville gives one fossil form, G. cyaihiformis, which has been accepted by 

 Jlilne-Ed wards and Haime as TurUnaria cyatldformis. 



% " Animaux inconnus, contenus dans des loges profondes, cylindriques, cannelees, et presque 

 lamellcuses a I'interieur, saillantes en forme de bouton, et eparses assez rtSgulierement a la surface 

 dun polypier calcaire, fixe, poreux, arborescent ou devcloppe on grande lame plus ou moins ondee 

 et pediculee."— p. 387. 



§ 'Beitrage zur Kenntniss der Corallenthierc des rothen Mccres.' 



