450 ZOOPHYTES. 



distinguished from that of the surculosa, by its terete medial branch- 

 lets, and rudely acervate marginal ; and also by the distinct star of the 

 cell. 



II. Caliculis tenuibus, orbiculato-nariformibus, aut appresso-tubiformibiis. 



15. MADREPORA ACULEUS. (Dana.} 



M. prostrata, ramis crassis (1-3") et valde irregularibus, ad extremum 

 valde et strict^ subdivisis, infra ramulis brevibus angulatis, horizontali- 

 bus, caliculis longe tubiformibus ; supra ramulis erectis et curvate surgen- 

 tibus, creberrimis, angulatis et attenuatis, 2'" crassis et sape 2" longis, 

 subacutis. Corallum caliculo apicali prominente (scepe 1'") ; laterali- 

 bus non confertis, parvulis, orbiculato-nariformibus, margine tenui; 

 cellu orbiculatd, sursum aperta, stella pkrumque conspicud, duabus 

 lamellis paulo latioribus. 



Prostrate, branches stout (1-3 inches thick), and very uneven, very 

 much and very closely subdivided ; below, branchlets short, an- 

 gular, horizontal, and covered with long tubular calicles; above, 

 branchlets erect, and rising with a curve, very crowded, angular, 

 and attenuated, 2 lines thick, and often 2 inches long, subacute. 

 Corallum with the apical calicle prominent (often a line) ; the 

 lateral not crowded, small, round-nariform, with the edge thin; cell 

 round, opening upward, star mostly distinct, two of the lamellse a 

 little the broadest. 



Plate 32, fig. 6, part of corallum, natural size; 6 a, branchlet, ditto; 

 6 b, profile of calicles. 



Feejee Islands. Exp. Exp. 



The specimen in the collections is a single horizontal branch eight 

 inches long. It is very much subdivided towards the apex, and bears, 

 above, a crowd of slender spike-like branchlets, rising with a curve, 

 and giving the corallum a bristled aspect. The branchlets, owing to 

 the rather distant calicles, which are sometimes in series, are very 

 uneven, or angular ; they are separated by intervals of about half an 

 inch. The calicles are about half a line wide, and a line long, and 

 are striate, though not echiriulately so. 



