Jan. 1904 ] Note on the Genus Harpochytrium. 
7 
peculiar proliferation of the sporangia is known in at least one 
other genus of chytrids, in Cladochytrium, according to Nowak- 
owski 8 in Cladochy triuni elegans (Tab. 6, Fig. 14-17) and ac¬ 
cording to Clinton in Cladochytrium alismatis 9 
Brief characterizations of the species might be given here 
with synonymy. 
1. Harpochytrium hyalothecae Lagerheim, Hedw., 29, 142, 143, 
1890. Plant body 20-60/* x 1.5-2/* attached at the basal end by a long 
and very slender stalk since the hosts are covered by a thick gelatinous 
layer; the base of the plant body is within the slime while the larger part 
projects beyond; fusoid and slightly curved, either projecting straight 
from the stalk, or bent, sometimes nearly to a right angle with it. Zoo¬ 
spores in one row, correspondingly small. Syn., Harpochytrium hyaloth¬ 
ecae Schroet. in Rabh. Krypt. Flora 4. Pilze, p. 114, 1892; Fulminaria 
mucophila Gobi, Script. Bot. Fasc. 15 , 283-292, 1899; Fulminaria mucoph- 
ila Wille, Nyt Mag. f. Naturvidenskab. 41, p. 175, 1903. Distribution, on 
Hyalotheca dissiliens, in Finnland, Sweden and U. S. of North America 
(Ithaca,, N. Y.) and on Sphaerozosma vertebratum, Cosmocladium spe¬ 
cies, Dictyosphaerium species, Finnland. 
2. Harpochytrium hedenii, Wille, Petermann’s Mitteilungen, Erg.- 
Heft no. 131, S. 371, 1900. Plants 80-180/* x 4-10A* the larger diameter 
accompanying the longer forms. Zoospores usually in a single row, 4-6/*, 
but in the broader forms in two to three rows. Plant sessile or with a 
very short stalk on some species of Zvgnema perhaps those species which 
have a thin gelatinous envelope (I have found that many of the threads 
of Zygnema from the Tibet material have a thin gelatinous sheath). Syn., 
Rhabdium acutum Dangeard, Ann. Mycol. 1, 61-64, 1903; Fulminaria hed- 
enii Wille, Nyt Mag. f. Naturvidenskab. 41, p. 175, 1903. Distribution, on 
.Spirogyra and Oedogonium, France; on different species of Spirogyra, 
rarely on Zygnema, rarely on Harpochytrium hedenii, U. S. of North 
America (Ithaca, N. Y.) ; on Zygnema and Spirogyra in Tibet, Asia; 
and on Zygnema in Patagonia, S. Am. 
3. Harpochrytrium intermedium Atkinson, Ann. Mycol. 1, 494 & 500, 
PI. 10, Fig. 22, 23. 1903. Plant body 40-70/* x 3-4/* narrowly fusoid, 
straight or slightly curved, sessile. Zoospores in one row, correspond¬ 
ingly small. 
EXPLANATION OF PLATE. 
(Plate reproduced from the November No. of Annales Mycologici.) 
Harpochytrium hedenii Wille. 
Figs. 1, 2, 3, 4, 5, Young stage of plant on Spirogyra and Zygnema, developed in 
cell culture, 
Fig. 6, Mature plant. 
Fig. 7, Old plant with two empty sporangia and young tertiary sporangium growing 
out in the old secondary one. 
Figs. 8, 9, Plants half grown showing large and long vacuoles separated by granular 
E rotoplasm. Both of these plants became freed from their attachment to the 
ost, the one illustrated in Fig. 8 was attached at two points, one point directly 
at the base, the other upon the side a short distance from the end. The plant 
in Fig. 9 was attached at one point on the side, a little distance from the end. 
Here the short slender stalk and the disk-like expansion is shown. The plants 
are usually attached directly at the end, but in some cases, probably where the 
zoospore rests at first against the host cell on its side, the haustorium and ab¬ 
sorbent disk are formed on the side. 
Fig. 10, Plant coiled in the form of a serpent on the side of the Spirogyra thread. 
Fig. 11, Old plant with empty sporangium and young secondary sporangium develop¬ 
ing within. 
8 Nowakowski, L. Beitrage zur Kenntnis der Chytridiaceen. Cohn’s 
Beitr. z. Biol. d. Pflanzen, 2 , p. 72-100, Tab. 3-6, 1876. 
9 Cladochytrium alismatis. Bot. Gaz., 33 , pp. 49-61, pi. 2-4, 1902. 
