940 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
TUBIDENDRID4}, new family. 
Trophosome. — Colony branching, polysiphonic, the hydrocaulus being, at least in part, covered with 
naked coenosarc. Ill-defined pseudo-hydrophores are often formed. Hydranths with two well-defined j 
whorls of filiform tentacles, a pyriform body and entirely naked pedicels. Stem beset with irregularly j 
distributed finger-like processes arising from the coenosarc. 
Gonosome. — Not known. 
BALEA Nutting, new genus. 
The generic characters of the type of this new family can not be defined so long as other members ’ 
of the family are unknown. The author takes pleasure in naming this remarkable genus after Prof. I 
W. M. Bale, the Australian naturalist, who has done such important work in the Hydroida of the ij 
Pacific. 
Balea mirabilis Nutting, new species. 
(PI. n, fig. 3; pi. vn, figs. 3, 4.) 
Trophosome. — Colony attaining a height of about 5 inches, flabellate in general outline; hydrocaulus 
polysiphonic, even to the tips of the ultimate branches, and at least partly covered with naked coenosarc, { 
which occupies parallel open grooves on the surface. Branches irregular, but laterally disposed on j 
the sides of the main stem, sometimes subdividing, and bearing irregularly disposed and often hardly | 
discernible hydrophores that are a mere thin rim around the naked bases of the hydranth pedicels. •• j 
Hydranths exceedingly irregular in their disposition, apparently most abundant on the distal parts of 
the colony, where they are sometimes aggregated in clusters; body pyriform, elongated, with a | 
proximal whorl of 12 to 16 filiform tentacles, and a distal whorl of larger filiform tentacles, which are 
8 to 12 in number and are inserted on the widest part of the body. The hydranths are borne on 
rather slender pedicels which are without a covering of chitin. Scattered irregularly over the stem 
and branches are a number of tentaculiform organs that are unlike anything else known to the writer, 
although they are likely to prove homologous with sarcostyles. They are apparently almost exactly 
like the smaller tentacles of the hydranth in general form and structure, as viewed under a fairly high 
magnification. They are composed of ectoderm and endoderm, but I have thus far failed to find any 1 '1 
nematocysts that are clearly defined. In form they have just about the proportion of length to breadth 
that is seen in the human finger. In life they are probably highly extensible, while in the preserved 
material they are contracted, in all likelihood, to their least dimensions. 
Gonosome. — U n k n o w n . 
Locality. — Station 3856, between Molokai and Maui islands, 127 fathoms. 
Cross sections of the stem or branches of this remarkable hydroid reveal a relation of tubes 
different from that found ijn any other that I have seen. The stem seems to be truly polysiphonic, the 
section showing a series of tubes much the same as one finds in some of the plumularians. The tubes, ■' 
however, open quite freely into each other through irregular apertures in their chitinous walls. The 
walls of the peripheral tubes are much thinner than those of the central ones, and sometimes their 
outer portions are entirely lacking, thus exposing the naked ccenosarc. While I have not ascertained i 
the manner of growth of this stem with certainty, it seems altogether likely that the coenosarc pushes 
through the openings in the walls of tubes already formed and creeps along the grooves between I 
adjacent tubes. At this stage we would have the condition of the ccenosarc on the surface of Hydrac- f j 
tinia, for instance. Later the coenosarc begins to form a thin layer of chitin on its outer surface, which 
arches over the groove and grows thicker and thicker, until finally we have a new tube of chitin with 
its usual ccenosarcal contents. 
Another point of difference between this form and the others described on page 938 lies in the fact ! 
that the hydranth arises from a single coenosarcal tube and not from several. In some cases it arises 
from one of the central tubes and in others from one of the superficial tubes, which indicates that the 
latter tubes have been formed after the appearance of the hydranth. 
The irregular disposition of the hydranths is another feature that is exceptional, although it is 
shared with the Hydrodendridae. 
Relationships of the Tuhidendridie. — The form of the hydranth is essentially that of the Tubularidae, 
especially as regards the disposition of the tentacles. It differs, however, in the relative size of the 
