(405] INVERTEBRATE ANIMALS OF VINEYARD SOUND, ETC. 111 
plants. The stem is very delicate, filiform, jointed, and at intervals 
gives off two very slender, opposite branches, which diverge at right 
angles, and in their turn branch at intervals in the same way. The 
cells are small and oval or elliptical, mostly arranged in clusters at or 
near the branchings of the stems, but some are often scattered on 
the branches; they are attached by a narrow base. It occurs both at 
low-water in pools and in shallow water among rocks. The V. armata 
is also a creeping species, but the cells are terminated by four conical 
prominences, each of which bears a slender spine when perfect. This 
also occurs both between tides and in shallow water, on hydroids and 
bryozoa. 
With these species of Vesicularia, and often attached to them and 
creeping over them, as well as on other kinds of bryozoa, hydroids, 
and algze, a very curious little species often occurs, in which the cells 
are small, campanulate, and raised on slender pedicels, which rise 
from slender, white, creeping stems. This is the Pedicellina Americana. 
The zodids, when expanded, display a wreath of twelve or more tenta- 
cles; in contraction and when young they are often clavate. 
The Mtea anguinea has not been recorded as from our coast, but is very 
common on rocky and shelly bottoms, creeping over various hydroids, 
alge, ascidians, broyozoa, &c.; it also frequently occurs on floating eel- 
grass and algve, in company with many hydroids. It consists of delicate, 
white, creeping, calcareous stolons, from which arise elongated, slen- 
der, clavate, white, rigid, erect cells, with the aperture at the end; the 
narrower, pedicel-like portion of the cell is surrounded by fine, circu- 
lar, punctate stric. 
The Eucrate chelata is also a slender, creeping species, aud has some- 
what similar habits, but is much less common, and has been met with 
only in the deeper parts of Vineyard Sound on ascidians and hydroids. 
in this species each cell arises from the back of the preceding one, near 
the end, and bends upward and forward obliquely, the cell expanding 
from a narrow, pedicel-like, basal portion to a more or less oval upper 
part, with the aperture oblique and subterminal. This, also, is a new 
addition to the fauna of our coast, although, like the last, long well 
known on the coast of Europe. 
The Diastopora patina grows attached to alge and eel-grass; it forms 
little circular disks, with tubular cells arising from the upper surface, 
those in the middle being longest. 
The Tubulipora flabellaris frequently occurs attached to various kinds 
of slender-branched alge, such as Ahnfeltia plicata, &c. It forms small, 
blunt-lobed, coral-like masses, composed of long, crooked, tubular cells, . 
united by a porous mass at boas Toward the borders of the lobes the 
cells are crowded and polygonal. In the central parts they are more 
cylindrical and form groups or radiating rows. Associated with the 
preceding on the alge, Crisia eburnea, (p. 311;) Mollia hyalina, (Plate 
XXXIV, fig. 264;) Cellepora ramulosa, (p. 312;) and other species oc- 
