80 



F. Oltmanns, Morphologie und Biologie der Algen. I, Jena 1904, II 1905. 



F. ScHMiTz und P. Hauptfleisch, Helmintliocladiaceae. Engler u. FrantI, Natiirl. Ptlanzenfam. I, 2, 1896 p. 327. 



F. ScHMiTZ, Untersuchungen iiber die Befruclitung der Florideen. Sitzungsber. d. Akad. Wiss. Berlin 1883. 



G. Thuret in Le Jolis, Liste des Algues marines de Cherbourg. Cherbourg 1864, p. 104. 



Fam. Helminthocladiacese. 



Tribe Ch a n t r a n s i e ae. 

 Chantransia (D. C). 



As shown by Thuret (1864 p. 104), Elias Fries was the first to define the 

 genus Chantransia in such a manner that it had a natural limitation, and one 

 could clearly see what plants it comprised. It was better characterized in 1864 by 

 Thuret who emphasized the fact that it has no tetrasporangia but only mono- 

 sporangia. He mentioned at the same time the antheridia of Ch. corymbifera, and 

 in 1876 (Notes alg. I p. 16) he described in conjunction with Bornet the sexual re- 

 production in this species, and the genus came thus to comprise species with and 

 without sexual reproduction (comp. Murray and Barton (1891)). In 1904, however, 

 Bornet has proposed to separate the species with sexual reproduction from those 

 bearing only sporangia, the first being kept in the genus Chantransia, while the 

 others are referred to the genus Acrochcctiuin Naegeli (1861), which might otherwise 

 be regarded as synonymous with Chantransia. I do not make this distinction in 

 what follows, as I have arrived at the view that it would not lead to a natural 

 classification of the species. In several cases there is great resemblance and pro- 

 bably also relationship between species with and without sexual reproduction, as 

 e. g. between Chantransia hallandica and haltica, Ch. efflorescens and Ch. pectinata, 

 Ch. Thuretii and Ch. Daviesii , and on the other hand the sexual species are mutu- 

 ally very different. That is also evident from Bornet's paper (1904) in which the 

 species are divided after the differences in the basal portion of the frond, while in 

 every group distinction is made between the asexual species, referred to Acrochce- 

 tium, and the sexual ones, referred to Chantransia. There is in reality no other 

 difference whatever between the two genera than that of the presence or absence 

 of sexual reproduction. It would, in my opinion, be equally justifiable to remove 

 from other genera of Floridea? all the species in which only tetrasporangia are 

 known. Undoubtedly, sexual organs will later be found in some of the species 

 hitherto known as only asexual, as I have succeeded in detecting them in Ch. hal- 

 landica, where Kylin had only described monosporangia , but on the other hand 

 there is no doubt that many species are really devoid of sexual organs. 



The great number of species described below will certainly appear surprising 

 to many phycologists; it is the result of a careful search through a large material 

 of Algse. Many of them are very small and inconspicuous and need careful exa- 

 mination for determination. It is therefore not to be wondered at that they have 

 been overlooked or perhaps so incompletely described that it is impossible to re- 

 cognize them. 



