GENERAL SYSTEMATIC BACTERIOLOGY 345 



Trichomata aut libera aut adhaerentia, simplicia, plerumque distincte articu- 

 lata et vaginata, rarissime oscillantia, singula vel fasciculata, plerumque in stra- 

 tum compactum saepe longe lateque ditTusum, tenue (VIX lineam crassum) vel 

 superimpositione ad poUicem usque incrassatum, spongiosum, interdum stratose 

 zonatum et varie coloratura dense intracata. Propagatio adhuc ignota. 



The following genera are included: Leptothrix Kuetzing, and Hy- 

 pheothrix Kuetzing. 



This name is the equivalent of Leptotricheae {q.v.). Robin (1853, 

 p. 345) used this family name with the description given by Kuetzing, 

 with the following addition: "Filaments tubuleux, delies, 

 continus, sans articulations, prives de mouvement, remplis d'un 

 contenu (endochrome) confluent, indistinct. Cellules propagatrices 

 speciales nulles ou inconnues." It was also used b}-- Hansgirg (1888, 

 p. 230) as the first subfamily of Lepiothrichaceae including the single 

 genus Leptothrix Kuetzing. 



Leptothricheen. A family name used by Zopf (1884, p. 45) with 

 the diagnosis: "Sei besitzen Coccen-, Stabchen-, Fadenformen (welche 

 einen Gegensatz von Basis und Spitze zeigen), und Schraubenformen." 

 He included the genera Leptothrix, Beggiatoa, Crenothrix and Phrag- 

 midiothrix. Hueppe uses the same term (1891, p. 30) with the de- 

 scription : "Leptothricheen bilden im vegetativen Stadium Stabchen- 

 welche meist langere Faden bilden." Baumgarten (1890 p. 127) de- 

 fines the term as a genus (Gattung), following Zopf in his definition, 

 and terming Zopf's genera "Untergattungen." It msiy be regarded 

 as the equivalent of Leptothrichaceae and Leptotrichaceae (q.v.). 



Leptothrix. This genus was proposed by Kiitzing (1843, p. 198) 

 for a group of algal species with the following description "Trichomata 

 simplicia tenuissima, monogonomica, turgida, continua, vel obsolete 

 articulata, in stratum vel caespitosum vel compactum, continuum, 

 plerumque late expansum complicata." Four species are included, 

 Leptothrix ochracea (Lyngbya ochracea Leibl.), L. aeruginea, L. lutes- 

 cens (Hygrocrocis ochracea Ag., Calothrix lutescens Meneghini) and L. 

 fontana (Hygrocrocis olivacea Kg. Bangia tenuis Kg.). The first species 

 described (L, ochracea) may be taken as the type. Its description is 

 as follows: 



L. fluctuans, natans, ochraceae; trichomatibus curvatis, intricatis, subtilis- 

 simis (diam. 1/1500-1/1200'"); articulis globosis vel oblongis. In Eisenquellen, 

 besonders auf sumpfigen Wiesen und in seichten Graben. 



