Phycologlcal studies— I. New Chlorophyceae from Florida 



and the Bahamas 



Marshall Avery Howe 



. (With plates 11-15) 



Halimeda scabra sp. nov. 



Usually dark green, fading to a yellowish green on drying, 

 strongly calcified and commonly rough to the touch, erect or as- 

 cending and forming clusters 6-9 cm. high or sometimes reclinate 

 among other algae and reaching a length of 25 cm. : branching 

 mostly dichotomous, usually frequent or somewhat congested, 

 rarely sparing : segments plane, enervate, discoid, subreniform, 

 suborbicular, or occasionally deltoid-obovate, 4—14 mm. broad, 

 0.6-1.5 ^^- thick, margin entire: peripheral utricles hexagonal 

 in surface view, 27-50/i in diameter, varying from subturbinate to 



subfusiform in lateral view, 70-240// long, galeate, |-|- of the 



length consisting of the acuminate, often indurated terminal cusp ; 

 lateral walls in contact for only a small fraction of their length, 

 easily separating on decalcification, usually somewhat thickened 

 or gibbous at the angles of contact: filaments of the central strand 

 fusing in twos or threes at the joints : sporangiophores 1.6—2.5 

 mm. long, rarely simple, mostly once or twice dichotomous, some- 

 times subracemose, irregularly proliferous, or in part cymose, fring- 

 ing the margins of the segments or now and then scattered on 

 the flattened faces, each commonly springing from the fusion of 

 two central filaments; the pyriform sporangia 0. 16— 0.32 mm. 

 broad, for the most part alternately distichous on the ultimate 



branches. (Plates ii and 12.) 



Not uncommon on the coast of Florida and the outlying keys 

 from Jupiter Inlet to Key West ; also in the Bahama Islands. 

 It grows on a rocky bottom or about the bases of sponges, from 

 low-tide mark down to a depth of at least three meters. The 

 description has been drawn from a study of thirty or more speci- 

 mens, representing about as many localities, but our fertile spcei- 

 men no. 2p0j from Sands Key, Florida (March 30, 1904), which 

 has furnished material for figures 2 and 3 of plate i I and for 

 FIGURES I, 3, 5,* 7-11 of PLATE 12, we cousidcr the nomenclatorial 

 type. 



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