284 Mr. 8. O. Ridley on Growth and Budding 
XXXII.—Onthe Classificatory Value of Growth and Budding 
in the Madreporide, and on a new Genus illustrating this 
point. By Stuart O. Ripiey, M.A., F.L.S., &., As- 
sistant in the British Museum (Natural History). 
[Plate XI.] 
THE manner in which growth is effected in the corallum has 
long been considered a character of very great importance for 
the systematic division of the Madreporaria. 
Thus MM. Milne-Edwards and Haime (Hist. Nat. Corall.) 
appeal constantly to the characters gemmiparity and _fissi- 
parity, and the various modifications of gemmiparity, in the 
formation of their genera, and (e.g. Astrangiaceee, Oculinide) 
sometimes in the distinction of larger groups; they point out 
at the same time that gemmiparity may occur in a group 
(‘Turbinoliidee) whose members are not normally compound. 
In the genus Madrepora the characteristic form of increase 
has been held by the highest authorities to be that of lateral 
extracalicinal gemmation from a primary zooid. ‘Thus 
Ehrenberg (Cor. roth. Meer. p. 108) defines that section of 
his family Madreporina which he calls Heteropora, but which 
is now termed Madrepora, as follows :—“ Stella ramulorum 
qualibet solitaria, gemmipara, seepe maiore (gubernatrice), 
reliquis raro gemmiparis, minoribus (frutices erectos, ramo- 
sissimos, prostratosve formant).” 
Dana’s generic diagnosis of Madrepora (U.S. Expl. Exp. 
Zooph. p. 431) 1s :—* Patrio-ramose ; arborescent, ceespitose, 
or, through coalescence, reticulate or foliaceous. Coralla with 
the branches terete (very rarely compressed) ; calicles regular.” 
He says further, “The genus J/adrepora includes species 
which bud from a parent-polyp, with which each branch ter- 
minates. . . . But two or three species are known in which 
the apical polyp cannot be distinguished; and these form a 
conuecting-link between this genus and the following ” (the 
following genus is Manopora, Dana,=Montipora, De Blain- 
ville). The three species mentioned by Dana as not having 
an apical polyp are J. cuneata, labrosa, securis. 
Milne-Edwards and Haime (Hist. Nat. des Coralliaires, 
p. 152) define Madrepora thus :—‘ Polypiérites réunis en 
masses ramifiées, fasciculées ou lobées. Calices saillants, au 
moins dans le jeune Age, & ouverture petite ou médiocre et 4 
bords assez €épais. Cloisons non débordantes. Columelle 
nulle;’’ and continue, pointing out that budding is usually 
circular and that “ le polypiérite souche de chaque pousse est 
