294 University of California Publications. [botany 



is certainly of the Viridia- group, dioecious and at least very near 

 to this species as understood by one of us in Collins, Holden and 

 Setchell, P. B.-A., Fasc. IV, No. 190, 1896. 



Chantransia secundata Lyngbye. 



On hydroids. San Juan Island, Wash., Tilden, No. 308!, 

 under Gallithamnion seeundatwm. 



The specimen in our. copy is sterile and looks more like Ch. 

 Daviesii (Dillwyn) Thuret. 



Family CrLFTANGIAl'E.F. 



Whidbeyella Setchell and Gardner gen. now Chaetangia- 



cearum. Plates 23, 24. 



Frond flat, membranaceous, composed of coarse filaments 

 running longitudinally in the medulla and curving outward to 

 the periphery, which branch di- to trichotomously and whose 

 terminal cells form the single peripheral layer of the frond; 

 rhizoidal filaments abundant, forming the greater portion of the 

 thickness of the frond, slender, with somewhat of a longitudinal 

 course; cystocarps scattered through the substance of the frond, 

 not projecting above the surface, opening by small carpo- 

 stomes on either surface, with the procarpic branch remain- 

 ing and forming a distinct pedicel of several cells; "fruit cav- 

 ity piriform, enclosed by a wall of several layers of delicate, 

 parallel, concentric bracteoid filaments and lined with the slender 

 gouimoblastic filaments which send out branches into the fruit 

 cavity, which bear the spores singly at the joints; spores ellip- 

 soidal. 



The description of this proposed genus, must necessarily 

 remain somewhat imperfect, since we have only a single battered 

 specimen with immature cystocarps. The structure, however, 

 of both frond and cystocarp is so distinct that we feel fully 

 justified in publishing it. It is intermediate between Galaxaura, 

 which it resembles fairly closely in its cystocarp. and Chaetangium 

 which it resembles in its frond. Its structure is different from 

 the latter in having an external tissue of a single laver of cells 



