256 ZOOPHYTES. 



in some parts, they are below much inflated and spongy in others; 

 the summits are usually very fragile, and often thinner than paper. 



The Mceandrina deedalea of Lesueur, from Guadaloupe, (Mem. du Mus., vi. 281, pi. 

 16, fig. 9,) appears to be this species. He describes it as having either simple or com- 

 pound disks, the longest containing seven or eight confluent polyps. The tentacles were 

 in two ranges along the sides of the cells. Colour fine reddish-brown, with green and 

 brown. Ridges of corallum angular, with the furrows either elongate or a simple star ; 

 the lamellae denticulate, and alternating with those of the adjoining furrow, and so united 

 as to form a zigzag line along the summit. Esper, Fortsetz. ii. tab. 87 ? 



The Aslrcea varia has the general habit of this species, excepting that the cells are 

 simple. 



II. Gyris valdc elongatis. 



3. MEANDRINA LABYRINTHICA. (Ellis.) 



M. hemispherica ; discis linearibus longissimis, gyrosis; gyris 3-4'" latis. 

 Corallum subcellulosum, robustum; collibus triangulatis, subacutis, 

 apice fere nudis ; septis viz turgidulis ; lamellis subcequalibus, denti- 

 culatis, basi paulum dilatatis ; transverse secto, septis solidis, vix \'" 

 crassis, paucis cellulis. 



Hemispherical; linear disks very long and gyrose; gyri 3 to 4 lines 

 broad. Corallum subcellular, firm ; ridges triangular, subacute, 

 nearly naked at top ; septa very slightly turgid ; lamellae nearly 

 even, denticulate, somewhat dilatate at base: in a transverse sec- 

 tion, septa solid, with rarely a cellule, scarcely 1 line thick. 



Plate 14, fig. 1, section of fossae and profile of lamellse. 



The West Indies and Bermudas. The Red Sea. Ehrenberg. 



The M. labyrinthica is one of the largest and best-known species of 

 the genus. Its hemispheres are sometimes six feet or more in dia- 

 meter. The thickness of the solid septa, and the triangular ridges 

 bare at top, are its most obvious characters. The bottom of the fossae 

 is narrow convolute-porous. The lamellae are even and numerous, 

 about sixteen being counted in half an inch. In worn specimens, the 

 ridges, owing to the thick solid septa, always remain more or less 

 prominent. 



According to Lesueur, who examined a live specimen at St. Thomas 



