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REPORT OF THE COMMISSIONER OF FISH AND FISHERIES. 143
has never yet been found with cystocarpic fruit, the genus being referred to the present suborder in
consequence of the resemblance of the frond to that of Dumontia. According to Bornet, the spores in D.
filiformis are borne directly on the carpogenic cell, whereas in the nearly related genera of
Cryptonemieæ there are sterile cells between the spores and the carpogenic cell.
HALOSACCION, Kütz.
(From αλς [als], the sea, and σακκιον [sakkion], a small sack.)
Fronds hollow, tubular or sack-shaped‚ simple or proliferously branched, consisting
of an internal layer of large, roundish, angular, colorless cells, usually arranged in
linear series and packed closely together by a gelatinous substance; tetraspores
cruciate, immersed in the cortical layer; cystocarps?
A small genus, including about ten species, of which H. ramentaceum is common in the North Atlantic,
the other species being confined to the North Pacific and extending as far south as California on the
east coast and Japan on the west coast. The species are all coarse and somewhat cartilaginous, and are
either in the form of elongated obovate sacks or tubular and proliferous. The cystocarpic fruit is
unknown, and the genus is placed conjecturally near Dumontia in consequence of the structure of the
frond.
H. RAMENTACEUM, (L.) Ag. (H. ramentaceum, Ner. Am. Bor., Part II, Pl. 29 a.—Ulva
sobolifera, Fl. Dan., Pl. 356.)
Fronds brownish purple, six to fourteen inches high, cylindrical-compressed,
attenuated at the base, simple or irregularly branched, more or less densely beset
with scattered or crowded, simple or forked, lateral proliferations; tetraspores large,
spherical, cruciate; cystocarps?
Var. GLADIATUM, Eaton, Trans. Conn. Acad., Vol. II, p. 347.
Proliferations long, simple, somewhat incurved, inflated.
On algæ in deep pools and on mud-covered rocks at low-water mark.
From Gloucester, Mass., northward; North Atlantic and Pacific. The variety at
Eastport.
A characteristic species of our northern coast, occasionally found at Gloucester and becoming very
common at Eastport. The fronds are very variable in shape, yet, on the whole, easily recognized. The
most marked form is the var. gladiatum. The robustness depends a good deal on the place of growth. In
exposed pools the fronds are short and very densely proliferous; in sheltered harbors, like that of
Eastport, the proliferations grow long, and are of rather delicate texture, approaching H. microsporum,
which hardly seems a distinct species. Kjellman, in Spetzbergens Marina klorofyllförande Thallophyter,
mentions certain hemispherical protuberances on the fronds of this species, and the same are found on
our coast. As before stated, the specimen of Asperococcus compressus credited to Gloucester, Mass., was
an error, the specimen being in reality a sterile and partly bleached Halosaccion.
SUBORDER GIGARTINEÆ.
Fronds terete, compressed or membranaceous, fleshy or cartilaginous; antheridia in
superficial spots or sunk in small crypts; tetraspores