Myxonema 208 



New York : Botanical Garden, August to October (458, 497), 

 June (612,631); Manhattan, June (615, 640, 625), September 



(478). 



This species, together with M. lubricant, seems to have under- 

 gone a gradual course of misinterpretation, until by DeToni it is 

 explicitly described as not setiferous, while the variety lubricum 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. 



Kutzing'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 lubricum 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; Kiitz. Spec. Alg. 353. 

 1849; T ab - Phyc. 3: pi. 2. f. 4. 1853. Rabenh. Flor. Eur. 

 A1 g- 3: 376. 1868. Cooke, Brit. F. W. Alg. 189. pi. 73. f. 2. 

 1883. Wolle, F. W. Alg. in. pi. 96. f. 1. 1887. DeToni, 

 Syll. Alg. 1 : 201. 1889. 



Stigeoclonium Borminanum Anzi, Erb. Critt. Ital. 1034.. 



