192 CHAETOPHORACEAE 
Forming a furry coating on dead straws and leaves, in stagnant 
water and in running water of a watering-trough ; also in tufts on 
the sides of a rocky spring. 
CONNECTICUT : Plymouth, March (524). 
New York: East Chester, May (392B); Central Park, June 
(61 3B). 
The opinion expressed by Schmidle that this species is quite 
distinct from M. Kuetzsingianum is abundantly confirmed by com- 
parison of American specimens. Most of the specimens on which 
the above description is based agree quite exactly with Raben- 
horst's type material (Alg. Sachs. 829). The length of the cells 
as here given is greater than that given by Schmidle, but hardly 
greater then in some of Rabenhorst’s plants. 
The plants from Central Park are rather shorter and finer, so 
that we at first identified them as Microthamnion vexator Cooke 
(Grevillea, LE! 75. 1882; Brit F. W. Ale 188. A. 75. 7. t. 
1883), but they are marked by a very strict or appressed habit of 
branching, while Cooke's figures represent a plant with very open 
branching. We have, therefore, included these plants in M. stric- 
tissimum, for there is no divergent character of sufficient importance 
to warrant making a new form. Indeed it is probable that M. 
vexator should not be maintained even as a variety of M. strietissi- 
mum, for though Cooke states that his plant is very much more 
slender than the latter species, the diameter he gives (3 رم‎ is not 
less than that of many plants of M. strictissimum. Furthermore, 
the measurements of M. verator based on Cooke's original speci- 
mens, as given by Nordstedt (Svensk. Vet. Akad. Hand. 22^: 15. 
1888), are so similar to those of the type material of M. strictissi- 
"uni, that we fail to see how it is possible to separate the two forms. 
MICROTHAMNION STRICTISSIMUM MACROCYSTIS Schmidle, Hedwigia, 
38: 169. pl. 7. f. 1-3. 1899 
Plants 300-800 » tall, branching more open ; branchlets as- 
cending or spreading, slender, and tapering slightly. toward the 
end; cells 2.5-3 £ (rarely An below) in diameter, 6-12, or 20 
times as long ; chromatophore pale and narrow, not encircling the 
cell, the tips of the apical cells hyaline (ei 27, کر‎ 7). 
EQ €‏ سج ہب سس یی 
