MYXONEMA 203 
New York: Botanical Garden, August to October (458, 497), 
June (612, 63 1); Manhattan, June (615, 640, 625), September 
(478). 
This species, together with M. dubricum, seems to have under- 
gone a gradual course of misinterpretation, until by DeToni it is 
explicitly described as not setiferous, while the variety /udrzicum is 
said to be setiferous. As a matter of fact the reverse is nearer the 
truth. The beautiful figures of Agardh, as well as his original 
description, clearly represent a form in which the branchlets are 
often more than subulate ; they may be even rather long setiferous. 
On the other hand the branchlets of M. lubricum are more often 
short-pointed. It is, of course, a matter of some difficulty to de- 
termine certainly the true character of an old species like this, but 
the plants on which our description has been based agree as_ 
closely as possible with the above-mentioned original figure and 
description. 
Kützing’s figure does not appear to be characteristic. In our 
judgment it resembles the young forms which are commonly found 
and which cannot certainly be identified with any particular species. 
Perhaps this figure has given rise to the incorrect notion of the 
species that has become prevalent. 
The species is variable, the branching less dense and less uni- 
formly opposite than in other members of the /uóricum group, and 
it therefore forms a point of transition to the alternate-branched 
species. 
The best specimens of M. tenue seem to reproduce M. lubricum 
in miniature, but there is no evidence that the two species inter- 
grade; in fact where both forms have been found growing to- 
gether they have appeared most distinct. 
7. Myxonema thermale (A. Braun) 
Stigeoclonium thermale A. Braun; Kitz. Spec. Alg. 353. 
1849; Tab. Phyc. 3: oi 2. f. 4. 1853. Rabenh. Flor. Eur. 
Ale. 3: 376. 1868. Cooke, Brit. FW Alg. 189. pl. 75. f. 2. 
4883. Wolle, F W. Ale. 111. 24 06. f. T- 1887. DeToni, 
Syll. Alg. 1 : 201. 1889. 
Stigeoclonium Borminanum Anzi, Erb. Critt. Ital. 7034. 
