146 Ulothricaeae 



times not completely encircling the cell), enclosing one to several 

 pyrenoids. 



Asexual reproduction by means of zoospores, formed to the 

 number of 1-4 m any cell ; they are 4-ciliate, furnished with a 

 red eyespot, and germinate immediately, forming a holdfast. 

 Akinetes are also formed. 



Sexual reproduction through conjugation of biciliate gametes 

 of which 8 or more may be formed in a cell. 



Inhabitants of fresh and salt water. Type, U. tenuis sitna 

 Kiitz. [Etym. odXoq, crisped, and dpc£, hair.] 



European algologists like Hansgirg and DeToni, who have con- 

 tended for the prevalence of Hormiscia over Ulotlirix on the 

 ground of priority, appear to have overlooked the real date of 

 Ulothrix. It is referred to by Kutzing himself in the Species Al- 

 garum as founded on U. tenuissima Kiitz. Alg. Dec. 144. 1836. 

 Actually, the genus was founded three years earlier by the de- 

 scription of this species as the type (7. e., the first in order), and 

 the addition of well-known Conferva species, notably C sonata 

 Web. & Mohr. Unquestionably, then, Ulothrix has the claim of 

 priority over Hormiscia Fries, 1835. 



As a matter of fact the two genera should never have been 

 treated as synonymous, for Hormiscia originally included only Con- 

 ferva penicilliformis Roth and C. Wormskioldii Flor. Dan., both of 

 which have recently been acknowledged to belong to Urospora 

 Aresch. rather than to Ulothrix. Rabenhorst ('47) at first em- 

 ployed Hormiscia in its correct, restricted sense ; but in his final 

 work (Flora Europaea Algarum) he adopted the erroneously en- 

 larged sense of Areschoug ('66), who had placed with Hormiscia 

 penicilliformis (Roth) Fries, Ulothrix sonata (Web. & Mohr) Kiitz., 

 a species which never belonged in such an affinity. At the same 

 time Areschoug had established a new genus Urospora on a sup- 

 posed new species U. mirabilis. In 1874 Areschoug discovered 

 that his Urospora mirabilis was identical with Hormiscia penicilli- 

 formis (Roth) Fries, but instead of reducing his genus Urospora 

 to synonymy, as he should have done, he created the new com- 

 bination Urospora penicilliformis. 



The fact that Hormiscia has been recently employed in the 

 incorrect sense inaugurated by Areschoug and continued by 

 Rabenhorst, does not militate against the necessity of reviving it 



