190 REPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Fronds compressed, ancipital, branches pectinate-pinnate, covered 

 everywhere, except at the tips, by polygonal, arealated cells. 



Ptilota. 



61. Fronds dichotomous, tips usually .incurved Ceramium. 



Fronds pinnate, main branches corticated throughout with cells 



arranged in transverse bands, secondary branches corticated only 

 at the nodes Spyridia. 



62. Fronds nearly black, substance dense 63 



Fronds rose-colored or purple, gelatinous or rather succulent, soine- 



" times capillary 64 



63. Fronds dichotomous, cylindrical, cartilaginous, spores borne in ex- 



ternal flesh-colored warts . . Polyides. 



Fronds filiform, rigid, wiry, irregularly branching, forming dense, 



intricate bunches Ahnfeldtia. 



Fronds small, compressed, pinnate, forming small turfs, spores borne 



on an axile placenta in the enlarged terminal branches . . Gelidium. 



64. Cystocarps immersed in the fronds » 65 



Cystocarps external, ovate or urceolate 70 



65. Fronds gelatinous, composed internally of a dense mass of slender 



longitudinal filaments, which give off short, corymbose, lateral 



branches, which form the cortex 66 



Fronds succulent, consisting of an internal layer of slender longi- 

 tudinal filaments and a cortex composed of roundish polygonal 

 cells, which become smaller towards the surface 69 



66. Spores arranged in regular radiating lines 67 



Spores in an irregular mass 68 



67. Cystocarps naked, cortical filaments free, often ending in hairs. 



Nemalion. 

 Cystocarps surrounded by a delicate membranous sack, cortical fila- 

 ments ending in large hyaline cells, which are adherent to one an- 

 other i Scinaia. 



68. Fronds dichotomous, subcompressed, central filaments fine and nu- 



merous Nemastoma. 



Fronds filiform, pinnate, central filaments few, rather large. 



Gloiosiphonia. 



69. Spores arranged in groups around a central placenta . . i . Bhabdonia. 

 Spores grouped in several irregular masses in the interior of the 



fronds Cystoclonium. 



70. Fronds traversed by a distinct central filament or siphon 72 



Fronds without a distinct central filament , 71 



71. Fronds succulent, brownish jmrple, cylindrical, beset with subulate 



branchlets, apices generally hooked, tetraspores zonate . . Hypnea. 

 Fronds red, somewhat rigid, filiform, tetraspores cruciate. 



Cordylecladia. 



72. Branches much contracted at base Chondriopsis. 



Branches not contracted at base , , ,-.,., 73 



