1915 Frye and Zellerj on Hormiscia 11 



gametes in all other species of Hormiscia have only 2. It was at first 

 suspected that there must be some mistake ; but repeated counts in ma- 

 terial gathered at various times showed constanth' 4 cilia. Even during 

 conjugation the J- cilia could be seen (Fig. 20). 



The general development and form of the plant is very closely like 

 that of other species of Hormiscia with the exception of the 4-ciliate 

 gametes. Thus it appears that this plant should be retained in the genus. 

 It is therefore designated and described as below. 



Hormiscia tetraciliata sp. nov. Marine. Filaments simple, 



moniliform, cylindrical, varying in diameter from 25 fi at base to 220 /x 

 at tip as a maximum, 6 cm. or less long, attached by the base to stones or 

 shells or Ulva laciuca in the lower littoral region ; holdfast a tuft of 

 branched nonseptate rhizoidlike diverticula arising 1 or 2 from each of 

 the lower 15 or fewer cells, descending within the sheath and pro- 

 jecting from its base, each branch flaring trumpetlike at its base. Cells 

 from half to twice as long as wide, more or less barrelshaped ; all cells 

 above the holdfast region similar, capable of division and of producing 

 zoospores or gametes; sheath in older cells as much as 15 /u, thick; 

 choroplast a rather close net, with many pyrenoids, lining the cell wall. 

 Asexual reproduction by akinetes or by zoospores ; zoospores very many 

 in a cell, pearshaped but the narrow end tapering into a long threadlike 

 projection, varying to more nearly spherical, tetragonal in cross section, 

 at the large end with 4 cilia about as long as the body, without "eye spot." 

 Gametes very many in a cell, spherical but without threadlike projection 

 like that in the zoospores, with red "eye spot," with 4 cilia shorter than 

 the body. 



The plant differs from the genus Hormiscia in so far as the species 

 have heretofore been reported, in that this plant has gametes with 4 cilia 

 while in the others they have only 2 cilia. It thus modifies our conception 

 of the genus. H. tetraciliata is nearest H. collahens (Ag.) Rabenh. and 

 H. incrassata (Kjellm.) Collins, but has larger cells than either of them. 

 It has been referred to H. wormskjoldii (Mert.) Fries, but differs from 

 that species in having much narrower filaments. By some authors this 

 species would undoubtedly be called Urospora tetraciliata. 



The plant has been found at the following places, all within 10 miles 

 of Puget Sound Marine Station: Point Caution; Goose Island, near Cat- 

 tle Point; on Ulva lactuca, just outside Newall's Lagoon; west side of 

 the mouth of False Bay, near Kanaka Bay; Turn Rock (Minnesota Reef) ; 

 just north of Hicks Bay on Shaw Island. 



