216 Chaetophoraceae 



This species is so very different in form from the globose spe- 

 cies of Chaetophora that one unfamiliar with it is likely to think of 

 it as an abnormally fasciated Draparnaldia. 



Doubtful Forms 



Chaetophora tuberculosa (Roth) Agardh, Syn. Alg. Scand. 

 129. 1817. Wolle, F. W. Alg. 116.//. ioj.f 11. 1887. 



Rividaria tuberculosa Roth, Neue Beitr. Bot. I : 285. 1802 

 (ref. from Cat Bot. 3: 341. 1806). 



There has been some diversity in the interpretation of this 

 species. Roth's description, notably the clause, " Ramis ramu- 

 lisque approximatis patulis sparsis," indicates a plant differing from 

 the erect-branched form illustrated by Kiitzing (Tab. Phyc. 3 : 

 pi. ig. f. 1) and Hansgirg (Prod. Alg. Bohm. 1 : 71. /. jo. 

 1886). These erect-branched forms correspond with our idea of 

 what C. pisiformis should be. 



Kiitzing's earlier figure (Phyc. Gen.//. 10. f. 2) and European 

 exsiccatae (Kiitz. Alg. Dec. Q2. Rabenh. Alg. Eur. ioyy. 

 Hauck & Richter, j8$. Wittr. & Nordst. 610b) seem to har- 

 monize better with Roth's description, but can hardly be separated 

 from tuberculose forms of C. elegans common with us. 



We should hardly wish to do away entirely with C. tuberculosa 

 on this evidence, but we can obtain no assurance of its occurrence 

 in this country, and possibly all specimens may be referred to 

 C. elegans and C. pisiformis. 



Chaetophora monilifera Kiitz. Spec. Alg. 896. 1849; Tab. 

 Phyc. 3: pi. 20. f. 2. 1853. Rabenh. Flor. Eur. Alg. 3: 384. 

 1868. Wolle, F. W. Alg. 118. pi. ioj.f 18 ', i 9 . 1887. 



The figure furnished by Wolle evidently represents only a 

 zoosporiferous state of one of our ordinary species. The speci- 

 men issued by Miss Tilden (Am. Alg. p) is of no greater value ; 

 it does not show the large thick-walled cells to be seen in Raben- 

 horst's specimen of C. monilifera. 



The suggestion of Schmidle (Hedwigia 36: 9-12. 1897), that 

 this species, as well as C. pachy derma Wittr., is only a form of 

 C. elegans in which the cells have largely developed into akinetes, 

 appears to contain much of truth. If, however, we accept the 

 view that these are only developmental forms, their names should 



