132 BULLETIN OF THE 



The coenenchyma is very delicate, filled with irregular scales, not imbri- 

 cated. The sclerenchyma is rather brittle, smooth, yellow, of metallic ap- 

 pearance, resembling brass wire. The polyps are alternate, subpeduncu- 

 late, numerous, though not contiguous, covered with scales like those of the 

 stem, and closed by eight blunt lancet-shaped scales. 



Acis solitaria Pourt. 



Corallum never branching, five or six inches long. Coenenchyma thick, 

 covered with large, elongated, flit- spicules, which become smaller and con- 

 verging on the not very prominent verruca-. Polyps in two rows, rather 

 closely set; a few scattering ones out of line. No longitudinal furrow. 

 Length 5 or 6 inches ; color whitish. 



In 200 fathoms. 



Isis flexibilis Pourt. 



Irregularly branching, subflabellate ; branches very long and slender ; 

 calcareous joints cylindrical, nearly smooth, or with a few faint striae, about 

 four times as long as the corneous ones in the thicker branches, but pro- 

 portionally much longer in the branchlets. Polyps rather thickly set, 

 generally alternate, short, campanulate, armed with short spines. The 

 thickest stems about X of an inch in diameter, the branchlets not much 

 thicker than horsehair ; the main stems were not obtained. Color dark 

 brown, from a thin coenenchyma covering the younger branches. 



In a few instances the branches appear to arise from the corneous joints. 



In 324 fathoms oil' the Florida reef. 



Mopsea eburnea Pourt. 



Arborescent, slender, dichotomous. Calcareous joints long, cylindrical, 

 faintly striated, seldom quite straight, not swollen at the ends. Corneous 

 joints very short. (In one case a long straggling branch entirely corneous 

 has grown from a calcareous joint, and bears four polyps.) Polyps scat- 

 tered, bright orange, g< nerally arising from the calcareous joints, but also, 

 occasionally, from the corneous ones, surrounded by a spirally twisted bundle 

 of strong spicules, of which eight longer ones project around the tent icles. 

 The latter are pinnate, and strengthened in their whole length by a chain of 

 blunt cylindrical spicules. The color of the whole corallum, with the excep- 

 tion of the corneous joints and the polyps, is pure white 



A fine specimen, 4 inches high, was obtained in ."» 1 7 fathoms off Som- 

 brero Light, Florida! — The diameter of the thickest part is fa of an ini h ; 

 the root, was not brought up. 



