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GOMPHONEMA GEMINATUM.
Tufted Gomphonema.
S P E C IF IC CHARACTER.
G omphonema g em in a tum ;> '& in ccespite ghhoso,fuscescente, dense intricatis.
G. filaments entangled, forming a dense, brownish, round tuft.
G omphonema g em in a tum , Ag. Syst. Alg. p. 12.
E chinella gem in a ta, Lyngb. Hydroph. p. 210. t. 70.
Vorticella p y ra ria , MiiU. Inf.'t. 46. f. 1,-4.
H ab. Attached to rocks and stones in alpine rivulets. Pentland Hills.
April and May. G. Walker A rnott, Esq. and D r G reville.
Tufts roundish, h a lf an inch to one inch in diameter, very soft and flaccid
of a greyish-brown colour. Filaments much branched in a dichotomous
manner, very slender, long, entangled, each branch terminating in two
wedge-shaped bodies, a t first united longitudinally, afterwards diverging
from each other. These bodies are hyaline, and contain a yellowish gra-
milated mass^ varying in size.
This species closely resembles the preceding, in the form
and apparent structure of its parts, under the microscope. But
It IS very many times larger ; and, instead of covering other
aquatic plants with a continuous mass of cottony, short filaments,
grows in round, dense, largish tufts, on stones and rocks
in alpine streams. The situation it seems to prefer is the bed
of the stream, where it can be exposed to the constant motion
of the water. I have seen the bottom completely concealed by
its crowded yet distinct tufts. It adheres to paper in drying,
but not so perfectly as the preceding.
Fig. 2. a, Gomphonema geminatum, natural size, b. Filaments; magnified.
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