22 
TRIBE I. ASTRiEACEA. 
Genus YI.— CAULASTE^A.— Dana. 
Segregato-gemmate, cespitose, with the stems and calicles snb- 
cylindrical. Coralla fragile, exterior striate, sometimes denticu- 
late; cell nearly orbicular, broadly excavate; lamellas unequally 
exsert, subentire, very numerous. 
1. Caulastra^a fcrcata {Dana). — Stems straight, furcating, scarcely un- 
dulate, .3 to 5 lines thick; disk of the polyps bright green. Corallum every 
where obtusely striate, smooth ; branchlets 1 to 2 inches long, alive for 4 to 6 
lines ; calicles often a little tumid, elliptical or orbicular ; lamellas numerous, 
1 line exsert, subentire, subequal, usually narrowing upward. 
Plate 9, fig. 4, animal unexpanded ; 4 a, one of the calicles ; 4 6, transverse 
section of the same ; 4 c, an enlarged lamella. — The Feejee Islands, in shallow 
water on the coral-reefs. — L xp. Exp. 
2. Caulastrjea distorta {Dana). — Stems contorted, 3 to 5 lines in diam- 
eter. Corallum every where striate ; branchlets shorter than in the preceding, 
alive for 3 to 6 lines ; calicles often tumid and distorted with the exterior la- 
mello-strisB finely spinulous ; lamellae numerous, subequal, 1 line exsert, their 
lateral surfaces finely plicate. 
Plate 9, fig. 5, corallum, natural size. — Feejee Islands. — Exp. Exp. 
3. Caulastra:a unuulata {Dana). — Hemispherical clumps, stems straight, 
crowded (i of an inch distant), subcylindrical, undulate. Corallum thick, 
throughout rugately striate and denticulate, calicles i an inch broad, some- 
times dilated and compressed ; lamellae numerous, triangular, subacute at 
apex and a little exsert, sub denticulate ; cell conical, bottom narrow, and of 
very open texture, 
Plate 9, fig. 6, profile section of calicle. 
Genus YII. — ASTE^EA. — Lamarck. 
Aggregate Astraaidse ; disks simple, rarely two or three 
mouthed; tentacles short. Coralla convex, usually neat hemi- 
spherical, rarely erecUgibbous, or glomerato-incrusting ; cells 
excavate, rnany-rayed, nearlj^ circular, sometimes angular or 
somewhat' lobed ; lamellae extending over the surface between 
the cells, and usually interrupted at the middle of the septum. 
