278 TUFTS COLLEGE STUDIES, VOL. II, No. 3 



two or more long, simple, sheathless setae ; chromatophore 

 single, parietal (with pyreuoid?). Reproduction unknown. 



D. SOLITARIA Collins, 1901, p. 242. Epiphytic ; cells 25-30/11 

 diatn., with wall 5-8 /u, thick, little or not at all lamellose ; setae 

 two, arising from the lower half of the cell, usually opposite, 

 straight, tapering, 4-6 p. thick at base. Fig. 99. On Laurencia 

 obtusa, Jamaica. 



W. and G. S. West published, 1903, p. 79, Polychaetophora 

 gen. n. Thallus minute, of few cells, filamentous, or some- 

 times unicellular; cells subglobose, ellipsoid or ovoid, mem- 

 brane very thick and strongly lamellate ; each cell furnished 

 with 8-12 long, flexuous, simple, sheathless setae; chromato- 

 phore single, parietal, often indistinct (with one pyrenoid?). 

 P. Ictonejlosa sp. unica, PI. CCCCXI/VIII, figs. 1-4. Characters 

 of the. genus. This seems to be quite distinct from Diplochaete ', 

 but G. S. .West; 1908, p. 279, PI. XX, figs. 1-6, published Poly- 

 chaclophora simplex sp. n. Cells subglobose or ovoid, membrane 

 thin and homogeneous ; dorsal part of each cell furnished with 

 2-4 long, flexuous, simple, sheathless setae. If the genus be 

 extended so as to include this species, it would certainly include 

 Diplochaete splitaria, and as the genus Diplochaete has priority, 

 that name must be used. It is unfortunate that a more appro- 

 priate name should have to give place to one less appropriate to 

 most of the species, but there seems to be no other course avail- 

 able than to revise the original description of Diplochaete, and to 

 include the* two British species of the Wests as D. lamellosa 

 (W. and G. S. West) Collins nov. comb., and D. simplex (G. S. 

 West) Collins nov. comb. 



2. ENDODERMA L/agerheim, 1883, p. 74. 



Frond microscopic, creeping on or within other algae or 

 aquatic plants ; filaments irregularly branched, with or without 

 hairs ; cell division mostly terminal ; chromatophore a parietal 

 layer with one or more pyrenoids ; zoospores 2-4-ciliate, with 

 stigma, formed 4 or more in a cell, escaping by a hole and soon 

 germinating ; asexual reproduction by biciliate zoogametes 

 without stigma is probable, but not certain. 



A genus of a few species, marine and fresh water ; ours all 

 with one pyrenoid and without hairs. 



