130 COLLINS AND HERVEY. 



Dasya Agardh. 



1. Divisions few, subsimple, ramelli very dense at tips. 1. D. ocellata. 



1. More branched; ramelli less dense at tips. 2. 



2. Ramelli all unbranched or forkings narrow. 3. 



2. Ramelli divaricately or squarrosely branched, at least near base. 5. 



3. Ramelli deciduous, leaving short, acute, spinous branches. 



3. D. spinuUgera. 



3. Ramelli more persistent; no spinous branches. 4. 



4. Ramelli very slender, short-celled, generally distributed on all but the 



oldest parts. 2. D. pedicellata. 



4. Ramelli larger, longer-celled, in more or less chstinct whorls. 



4. D. punicea. 



5. Ramelli stout near their base, diminishing at each forking, very slender 



at apex. 6. 



5. Ramelli nearly uniform in size throughout. 5. D. arbuscula. 



6. Ramelli forming a very dense coating, especially near tips of branches. 



6. D. ramosissima. 

 6. Ramelh in minute, subcorymbose clusters, not denser near apices. 



7. D. corymbifera. 



1. D. OCELLATA (Grat.) Harvey in Hooker, 1833, p. 335; 1846-51, 

 PI. XL; Cermnium ocellatum Grateloup, 1807, p. 34. Cooper's 

 Island, Feb., Farlow; on Sargassum, Gibbet Island, Jan., Gravelly 

 Bay, Feb., Hervey; tetraspores in Jan. 



2. D. PEDICELLATA Agardh, 1824, p. 211; D. elegans Harvey, 

 1853, p. 60; Kiitzing, 1864, p. 21, PI. LIX. Kemp, as D. pediculata; 

 Merriman; Miss Peniston; Miss Wilkinson; Shelly Bay, April, 

 Collins; Buildings Bay, March, Hervey. The common Dasya of the 

 Atlantic coast from Cape Cod to Florida, but evidently not common 

 here. Though the name D. elegans has been long familiar, it will 

 have to be given up for D. pedicellata, the priority of which is unques- 

 tionable. 



3. D. spinuligera sp. nov.; P. B.-A., No. 2188. Cellulis peri- 

 centralibus 5, corticatis, cortice glabro, continue, cellularum minorum, 

 elongatarum; ramis paucis, elongatis, ramulos breves, patentes, 

 acutos, gerentibus; apice ramuli junioris fasciculum densum ramel- 

 lorum ferente, adultioris nudo; ramellis densissimis, deciduis, mono- 

 siphoniis, dichotomis, rectis nee divaricatis, cellulis 2-3 diam. longis, 

 superne 1 diam. modo, diametro ubique aequali; stichidiis conicis 

 vel cylindro-conicis, prope basin fasciculi ramellorum ortis; tetra- 

 sporangiis 2-4 in verticillo; frondis substantia firma; colore rubro 

 obscuro. Plate IV, figs. 24-25. 



Pericentral cells 5, corticate, cortex smooth, even, of small elongate 



