190 University of California Piihlicaiions in Botany [Vol.8 



necessary to rely larjrely upon dried specimens or those preserved in 

 formalin. The resulting account which follows must, therefore be 

 regarded as tentative, but as put forth to indicate possibilities to be 

 tested through study of living material. The tendency of two or 

 more species to grow intermingled has often caused confusion in the 

 past, and may have passed unsuspected in our own examinations. 



As to reproductive processes, we have practically nothing new to 

 offer from our owti observations. Each species, however, should be 

 studied in cultures to determine its correspondence with, or deviation 

 from, the published statements for such species as have been investi- 

 gated. The size and shape of the zoospores and of the gametes should 

 be noted as well as the number of cilia present. This is especially 

 necessary in the case of the gametes as will be noted below under 

 Hormiscia tetraciliata Frye and Zeller. 



In considering the specimens studied, as well as the species de- 

 scribed, it seems possible to separate the genus Hormiscia into three 

 fairly readily distinguishable sections, as follows : 



Section 1. PenicilUformes. Segments shorter, or at most, very 

 little longer than broad, fertile cells only slightly swollen ; holdfast 

 consisting of extramatrical, generally divaricate rhizoids, or of intra- 

 matrical rhizoids ; chromatophore varying in the different species from 

 nearly imperforate to coarsely reticulate. To this section we are 

 inclined to refer the following described species : H. penicilliformis 

 (Roth) Fries, H. incrassata (Kjellm.) Collins, H. collahens (Ag.) 

 Rab., H. Hartzii (Rosenv.) Collins, H. crassa (Kjellm.) Collins and 

 H. tetraciliata Frye and Zeller, as well as Urospora hangioidcs (Harv.) 

 Holmes and Batt., U. claviculata Kjellm. and U. acrogona Kjellm. 



Section 2. Grandiformcs. Segments elongated, especially the 

 fertile segments, usually twice or more as long as broad in fertile 

 condition and not swollen; holdfast of intramatrical rhizoids (at times 

 free at the very base) and arising from a considerable number of the 

 lower segments; chromatophores, so far as known, coarsely reticulate. 

 To this section we are inclined to refer Hormiscia grandis (Kylin) 

 S. and G. and Urospora elongata (Rosenv.) Hagem. 



Section 3. W or mskioldii formes. Segments shorter or only slightly 

 longer than thick, the fertile swollen to spherical or to more or less 

 broadly or even ventricosely ellipsoidal ; holdfast of intramatrical 

 rhizoids arising from even as many as 25-30 of the lower segments 

 and, at times, free at the very base ; chromatophore from finely per- 

 forate to coarsely reticulate ; coarse plants with fertile segments from 



