DUMONTIACEAE. 535 



parts this axis is clothed and obscured by numerous decurrent rhizoidal fila- 

 ments. In the female plants, auxiliary-cell branches are numerous, consisting 

 of 5-9 enlarged subspherical cells near base, the special auxiliary cell occupy- 

 ing the middle of this enlarged portion and having little more than half the 

 diameter of the two immediately adjacent inflated cells. In the male plants, 

 the antheridia form subglobose tufts or clusters at or near the ends of the 

 peripheral filaments. The usually numerous cystocarps form granules ^j ra of 

 a line in diameter, easily visible under a hand-lens. The plant grows on rocks 

 in about ten feet of water in Castle Harbor and has been found washed ashore 

 at Spanish Point, Buildings Bay, and Shelly Bay. (Phyc. Bor.-Am. 1900 and 

 2196.) Apparently endemic. 



Dudresnaya bermudensis Setchell, is readily distinguished from the fore- 

 going by its much finer taper-pointed branchlets and more slender main axes, 

 these rarely more than J of a line in diameter, and by the moniliform, rather 

 than cylindric peripheral filaments, the outer cells subspheric, or ovoid or ellip- 

 soid and only slightly longer than broad. The cystocarps are many-spored 

 and sV-rV of a line in diameter. Cooper's Island (Farlow) and Building* 

 Bay (Hervey). (Phyc. Bor.-Am. 2195.} Apparently endemic. 



Dudresnaya caribaea (J. Ag.) Setchell, often resembles D. bermudensis 

 in habit, but is, generally speaking, a larger plant, 4-15 inches long, is more 

 obviously complanate-distichous, and its main axes are often 1-2 lines broad. 

 Microscopically, it shows moniliform peripheral filaments, much resembling 

 those of D. bermudensis, but the specialized auxiliary cell is enlarged, sub- 

 spheric, and terminal on the special auxiliary-cell branch, this consisting other- 

 wise chiefly of discoid cells, instead of being intercalary and scarcely distin- 

 guishable from its neighbors. The cystoearps are few-spored and have about 

 one-half the average diameter of those of D. bermudensis. Found floating at 

 Cooper's Island (Farlow}. Type from the Tortuga?, Florida. 



Family NEMASTOMATACEAE. 



Calosiplionia verticiUifcra (.T. Ag. ) Setchell, has been reported by Setchell and 

 by Collins as having been collected at Cooper's Island by Farlow in 1881. The 

 present writer has not seen the Bermuda plants that have been given this name, but 

 the single type specimen of Helminthiopsis verticiUifcra J. Ag., on which the name 

 rests, appears to have the auxiliary-cell branches of a Dudn-mnuin and, in fact, to be 

 distinguishable by no reliable character from Dudresnaya carHi/ni: (J. Ag.) Setchell, 

 the type of which also was from the Tortugas, off the coast of southern Florida. 



Platoma cyclocolpa (Mont.) Schmitz (type from the Canary Islands), or 

 an apparently sterile plant resembling it in general habit, is of occasional 

 occurrence in Bermuda. Its soft gelatinous flattened rose-purple thallus is 1-5 

 inches broad and high, irregularly dichotomo-multifid, or irregularly palmatifid 

 from a plane base that is often 1-2 inches wide, the margins crenate-dentate, 

 irregularly lobulate or bilobulate, or incised-dentate, the teeth mostly obtuse 

 and often subterete, the plane faces occasionally showing teeth or short pro- 

 liferations. In narrower forms, the main segments are sometimes irregularly 

 subpinnate or bipinnate. From the species of Halymenia, it is readily dis- 

 tinguished by the more obviously filamentous cortex and subcortex and by the 

 absence of anastomoses and stelliform cells. The Bermuda plants differ from 



