150 I OLLIN8 \\i> ill BVEY, 



Famli DUMONTIACEAE. 

 I ►udresnai a Bonnemaison. 



1. Peripheral filaments cylindrical or nearly l. D. erassa. 



1. Peripheral filaments distinctly moniUform. 2. 



2. Auxiliary cell terminating the auxiliary branch. 3. I), caril 



Auxiliary cell in middle of auxiliary branch. 2. D. bermud 



1. D. « RASfu Ilnwe. l'.ii.-. p. 572, II XXVm, XXIX. figs. l_> 26; 

 P. B.-A., X«-. L900, 2196. Castle Harbor, Spanish Point, July, 

 Howe; Castle Harbor, A. E. Wight in Farlow herb.; Salt Kettle. 



Feb., Buildings Hay. March. Spanish Point. .March. Ilcrvey; Shelly 



Bay, April, Collins. The plants from Buildings Hay, Spanish Point 



and Shelly Hay were washed ashore; at Salt Kettle. Paget, it grew just 

 below low water mark; at the type station in Castle Harbor it grew 

 at 3 m. depth at low water. It varies much in habit, from the form 

 with short, stout branches, figured by Howe, to forms with slender, 

 acute branches; from generally rounded outline to loosely pyramidal; 

 from forms so dense that when spread out on paper they cover it 

 continuously, without interstices between the branches, to quite 

 o] (ii specimens, all branches distinct. The largest plant noted was 

 about 25 em. high and 15 em. broad. Howe had only cystocarpic 

 plants when describing the species, hut we have found antheridia 

 equally abundant, always on separate individuals. The antheridia 

 are formed near the ends of the peripheral filaments, which here hear 

 short, erect lateral branches, usually covered with minute densely 

 branched ramuli of a few cells each, the terminal cell becoming the 

 antheridium. According to the length of the axis and the amount of 

 branching in the ramulus, the antheridia may he cylindrical, conical 

 or ovoid. Sometimes the antheridia are so abundant on the peri- 

 pheral filaments as to form a dense continuous mass, through which it 

 is difficult to see the filaments, except the tips, which project beyond the 

 antheridia. Both antheridia! and cystocarpic plants were distributed 

 a- P. B.-A., Xo. 1900. Some forms are habitually not unlike IK caribaea 

 and D. bermudensis, hut arc easily distinguished microscopically by 

 the character of the peripheral filament-. It i> often overgrown with 

 Acrochaetium corymbiferum, and when both have abundant antheridia, 

 it may he perplexing to one unfamiliar with the species. 



2. h. berm iiell. L912, p. -Ml, PI. XXYII. I 



P. B.-A., No. 2195. Cooper's [sland, Feb., Farlow, washed ashore 

 in abundance; Si 3, washed ashore, March. Hervey. 



