430 POLYPI. VAGINATI. 



P. furcata, Lam. Cespitose, many-stemmed, branched dichoto- 

 mously ; ramuli short, furcated ; stars contiguous, small, hollowed. 

 Lam. ii. 271- 



Gen. 18. ASTREA, Lam. Madrepora, Soland. 



Fixed, stony, incrusting marine bodies, or forming a hemispheri- 

 cal or globular mass, rarely lobed ; upper surface crowded 

 with orbicular or subangular lamellar and sessile stars. 

 * Stars separated from the base. 



A. radiata, Lam. Stars orbicular, concave, the margin elevated ; 

 lamellae narrow, the interstices sulcated. Inhabits American seas. 

 Ellis, Zooph. pi. 47, %. 8. 



A. Argus, Lam. Stars large, orbicular, with many rays ; margin 

 elevated, obtuse, and radiated exteriorly. Inhabits American 

 seas. Lam. ii. 259. 



** Stars contiguous. 



A. favosa, Lam. Subglobose ; stars large, concave, unequal, angu- 

 lar ; margin subacute ; walls multi-lamellar ; lamellae dentated. 

 Inhabits Indian Ocean. This species is found fossil in France. 

 Lam. ii. 263. 



A. denticulata, Lam. Stars unequal ; marginal lamellae elevated, 

 alternately large and small ; cells contiguous, without interstices 

 at their base. Indian Ocean. Ellis, Zooph. pi. 49, fig. 1. 



Gen. 19- EXPLANARIA, Lam. 



Fixed, stony, developing a free foliaceous membrane, waved and 

 sublobed, with one stelliferous face ; stars scattered, sessile, 

 more or less separated. 



E. infundibulum, Lam. Turbinated, infundibuliform, proliferous 

 within. Inhabits Indian Ocean Lam. ii. 255. 



E. mesenterina, Lam. (M. cinerascens, Ellis.) Variously convoluted, 

 twisted and sinuous ; interstices of the stars porous. Inhabits In- 

 dian Ocean Ellis, Zooph. pi. 43. 



Gen. 20. ECHINOPORA, Lam. 



Fixed, stony, flattened and extended into a free membrane, 

 rounded, filiform, and finely striated on both sides ; upper 

 surface crowded with small papillae, and convex orbicular stellar ; 

 papillae pierced with one or two holes, each covering a lamel- 

 lated star ; stars scattered, orbicular, covered. 



E. rosularia, Lam. Flattened, foliaceous, suborbicular ; the upper 

 surface covered with sharp and orbicular striae, the lower smooth, 

 striated. Inhabits Seas of New Holland. Lam. ii. 254. 



Gen. 21. MONTICULARIA, Lam. 



Fixed, stony, incrusting marine bodies, united into a subglo- 

 bular gibbous or lobed mass, or subfoliaceous expansions ; up- 



