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TRIBE III. MADREPORACEA. 453 



Plate 34, fig. 1, part of corallum, natural size ; 1 a, part of branchlet, 

 ditto ; 1 b, profile of calicles, ditto. 



Tahiti, Society Islands. Exp. Exp. 



The corallum is a circular stony plate, having the margin squar- 

 rosely incised or incipiently branching, and bearing above erect 

 finger-shaped branchlets. One of the specimens is two feet in dia- 

 meter, and the solid part is two inches thick at centre; it was attached 

 below by a small and short pedicel. This species resembles the nasuta, 

 but differs strikingly in having no distinct marginal branchlets. 



19. MADREPORA NASUTA. (Dana.} 



M. late cespitosa, breviter pedicellata, paulum convexa ; basi solida et 

 plano-obconica ; infra, complanata et subnuda, crasso-pedicellata ; 

 supra ramulis crebris, digitiformibus, subsimplicibus, raro proliferis, 

 subteretibus, 2-2" longis, et 4-5'" crassis, subacutis ; margine ra- 

 mulis horizontalibus elongatis. Corallum caliculis valde prominenti- 

 bus, subtiliter striatulis, compresso-nariformibus, stelld scepe conspicud, 

 duabus lamettis paulo latioribus. 



Broad cespitose, short pedicellate, a little convex, with a solid 

 plano-obconical base; below, complanate and nearly naked, stout 

 pedicellate; above, branchlets crowded, digitiform, nearly simple, 

 rarely proliferous, subterete, 2 to 2 inches long and 4 to 5 lines 

 thick, subacute, branchlets of the margin horizontal and elongate. 

 Corallum with the lateral calicles very prominent, compressed-nari- 

 form, very finely striate ; star often distinct, two of the lamellae a 

 little the broadest. 



Plate 34, fig. 2, corallum, natural size; 2 a, branchlet, ditto; 2 b, 

 profile of calicles. 



Tahiti, Society Islands. Exp. Exp. 



The stony compact base, formed from the coalescing of horizontal 

 branches, is six inches in diameter in a specimen which is twelve 

 inches across : from the margin of the base horizontal branchlets ex- 

 tend out, which are a little ascending and subramose. The plate was 

 attached below by a pedicel three and a half inches broad. The 



114 



