43 
No. 291. Spongia, ahenobarbus. 
The “ red beard ’ of our fishermen, who use it instead of a cloth for washing dishes. It is very abun» 
dant at Kavon Point, Bergen Point, and Staten Island, on old shells and oysters, below low water mark; it 
grows in large clusters from 6 to 12 inches high, and spreading on all sides to 5 or 6 inches broad; the po- 
lype and ova are deep red, which give a beautiful appearance to recent specimens; the dried polype for a 
long time communicates a foetid odor; when exposed to the sun and water, it soon bleaches to a dull ash 
color. 
No. 292. Spongia, arboreus . Aborescent, dichotomously branched. 
This beautiful sponge I found on two occasions at the mouth of the harbor, near the telegraph, Staten 
Island; it is cylindrical, much branched, ^ inch thick, and nearly equal throughout, except at axils, where 
the branches are woven together for some distance. I think its habitat is in the deep water of the lower Bay, 
between the Narrows and Sandy Hook. 
Genus, FLUSTRA. L. 
Crustaceous, cells more or less quadrangular, flat, the aperture transverse, val¬ 
vular. 
No. 293. F. membranacea. Lin. syst. Cells oblong, with a short blunt spine 
at each corner.— Ellis. 
On gracilaria and other Algae ; commencing at the base, surrounding the stem, and thence creeping up¬ 
wards to the apices, weaving a beautiful net-work, that appears to the unassisted eye like silver gauze or 
lace. Some fine specimens of this Coral are thrown on the shore at Jersey City; in one instance, a gracila¬ 
ria, with many branches and ramuli, was entirely entombed in its meshes. There are several species of this 
genus, and the entire genus is nearly allied to the Membranipora of Ellis; the Flustraof Linnaeus, as charac¬ 
terized by Cuvier, will include the whole, though Cuvier mentions a difference that would certainly amount 
to a generic separation :—“ D’apres les observations de Spallanzani, de MM. Audouin, Edwards, et de 
Blainville, certaines flustres seraient habites par de animaux du group des acidies ; mais il y en a aussi, qui 
bien certainement, d’apres MM. Quoy et Gaimard, le sont par des vrais polypes .”—Regne Animal , iii., 303. 
Grant says, “ The aperture of the cells is formed by a lid which folds down when the polype is about to ad¬ 
vance from the cell, and in F. truncata where the lid is very long; it appears through the microscope like 
the opening of a snake’s jaws.” 
