300 University of California Piihlicatimis in Botany [Vol.7 



latere inferno i']ii/.oi(lil)us imiltis gracilliinis, attenuatis et dendritice 

 raniosis in<luti.s; gciu'ratioiu' ignota. 



Filaiucnts repeatedly and ii'regulai-ly branched; cells very variable 

 in form and size, typically cylindrical, 4-7 fx. diam., 2-8 times as long; 

 elu'oiiiatopliore without jjyi-enoids. filling the cell; "sj)Oi'angia " narrow 

 to witle, bluntly conical, oO-TO/i. high, 25-60/a wide, developing many 

 very slender, attenuate, dendritically branched rhizoids from th(* lower 

 side ; reproduction unknown. 



Growing on dead clam shells. Neah Bay, "Washington. Type no. 

 3825, Gardner. 



In a Gomontia inhabiting certain shells from Neah Bay we have 

 found all the "sporangia" of the Acarid-type and with the processes 

 or rhizoids slender, branched, and attenuated to a jioint. The "spo- 

 rangia" seem so distinct from those of G. Bornctii that we de.scribe 

 the plant possessing them as new. In some shells we have found the 

 "sporangia" of this species intermingled with others. The vegetative 

 filaments of G. hahrorhiza seem less entangled and slightly larger than 

 those of either G. polyrhiza or G. Bornetii. 



Gomontia caudata sp. nov. 



Plate 23, figures 1, 2 



Filamentis brevibus, parce ramosis; cellulis 5.5-6.5^ diam., 2-12- 

 plo diam. longioribus; chromatophoris cellulas terminales et "spo- 

 rangia" juvena iinplentibus, in cellulis vetustioribus interruptis; 

 pyrenoidibus inconspicuis ; "sporangiis" (gametangiis ? aut aplano- 

 sporangiis ?) clavatis, 50-70//, latis, 160-200/x longis, inferne ad rhizoide 

 singula attenuatis, parietibus maturitate crassis, hyalinis, homogeneis ; 

 rhizoidibus saepe maxime incrassatis striatisque. 



Filaments short, sparsely branched ; cells 5.5-6.5/a diam., 2-12 times 

 as long; chromatophore covering the terminal cells and young "spo- 

 rangia," broken in the older cells; pyrenoids inconspicuous: "spo- 

 rangia" clavate, 50-70/^ diam., 160-200/x long, tapering to a single 

 rhizoid below with thick, hyaline, homogeneous wall at maturity ; 

 rhizoid often becoming much thickened and striated. 



Growing in shells of Mytilus californicus Conr. Neah Ba}-, Wash- 

 ington. Type no. 3825, Gardner. 



"We have found in shells of the larger edible mussel of our coast a 

 Gomontia with filaments seemingly less abundantly branched and 

 "sporangia" (aplanosporangia ?) with very thick walls and a .single 

 long rhizoid (cf. pi. 23, figs. 1, 2). These "sporangia"" bear a certain 

 resemblance to the "cells" figured by Lagerheim (1885, pi. 28, figs. 

 4, 6), but are, at least, thicker walled. The fact which seemed to 

 indicate distinctness was that only this ty])(' of "sporangium" was 

 found in the shells examined. 



