130 i i 'i UNA \\i> in i;\ i , > 



Dabya Agardh. 



l. DiviaionB few, subeimple, ramelli very dense al tips. l. D. oeellata. 



l. More branched; ramelli less dense at tips. 

 2. Ramelli :tll unbranched «>r forkings narrow. 



2. tlamelli divaricately or Bquarroeely branched, at least Dear base. 5. 

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



3. J), spinul . 

 3. Ramelli more persistent; do spinous branches. !. 



l. Ramelli very Blender, short-celled, generally distributed on all but the 

 oldest parts. 2. D. pedicellate* 



l. Ramelli larger, longer-celled, in more or less distinct whorls. 



4. D. punicea. 



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



at apex. 6, 



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



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



»'). I), ramosissima. 

 6. Ramelli in minute, Bubcorymbose clusters, not denser near api< 



7. D. corymbifera. 



1. I). o( l i.i.\t\ (Grat.) Harvey in Hooker, 1833, p. 16 51, 



PI. XL; Ceramium ocellatum Grateloup, 1807, ]). 34. Coo] 



Island, 1'Yl)., Farlow; on Sargassum, Gibbet Island, Jan., Gravelly 

 Day, Feb., Hervey; tetra spores in Jan. 



2. D. pedicellate Agardh, 1824, p. 211; J), elegans Harvey, 

 is:.:;, p. ii(i; Kutzing, L864, p. 21, II LIX. Kemp, as I), pediculata; 

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

 Collins; Buildings Bay, March, Hervey. The common Das\ i of the 

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



here. Though the name 1). rlnjans has been long familiar, it will 



have to be given up for I), pedicellate, the priority of which i- unques- 

 tionable. 



::. D. spinuligera sp. now; P. 15. -A., No. 2188. Cellulia peri- 

 centralibus 5, cbrticatis, cortice glabra, continuo, cellularum minorum, 

 elongatarum; ramis paucis, elongatis, ramulos breves, | 

 acutos, gerentibus; apice ramuli junioris fasciculum densum ramel- 

 lonmi 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 orris; tetra- 

 sporangiis 2 1 in verticillo] Frondis substantia firma; colore rubra 

 obscuro. Plate IV. figs. 24 25. 



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



