58 MARINE 



ORDER UDOTEACEJE 

 GENUS Fenicillus 

 The merman's shaving-brush, characteristic of coral reefs. 



P. dumentosus. Holdfast much branched, like a fibrous root, and 

 penetrating deep into the coral or sand ; stem short, thick, more or less 

 flattened, sometimes hollow, covered with velvety scurf; top covered 

 with loosely spreading tuft of soft filaments three to six inches long, 

 which branch repeatedly in pairs (dichotomous) ; color deep green. 

 When old, these plants are incrusted with a thin, porous layer of car- 

 bonate of lime. (Plate VI.) 



P. capitatus. Holdfast a dense mass of fibers two or more inches 

 long ; stipe one to five inches long, one fourth to one third of an inch in 

 diameter, usually cylindrical, sometimes wider at top than at base, 

 sometimes flattened ; thickly incrusted with lime, which is smooth and 

 often polished ; top a dense, spherical mass of filaments one to two 

 inches in diameter ; filaments branching dichotomously, and rigid from 

 incrustation of lime. 



P. Phoenix. Stipe cylindrical, one to three inches long, one fourth of 

 an inch in diameter, thickly incrusted with lime, smooth ; capitulum or 

 head ovoid, and composed of filaments which are incrusted with lime 

 and coherent, forming many distinct, flat, wedge-shaped, level-topped, 

 spreading laminae. This species is found at Key West. 



GENUS Udotea 



U. flabellata. Short, flattened stem, expanding into a broad, fan- 

 shaped, smooth frond, concentrically zoned ; margin wavy ; thickly 

 incrusted with lime. Abundant at Key West. 



U. conglutinata. Deeply descending root ; stem expanding into fan- 

 shaped frond ; entire, lobed, or irregularly torn ; slightly incrusted with 

 lime. The frond is composed of longitudinally parallel, adherent fila- 

 ments, which are visible, giving a striated, rough surface. (Plate VI.) 



GENUS Halimeda 



This genus resembles the corallines externally, and is abundant 

 on coral reefs. It appears as if formed of separate parts, resem- 

 bling a series of heart- or kidney-shaped segments strung together. 

 The plants are more or less incrusted with lime. The branching 

 holdfast grasps particles of sand, and with them forms a solid 

 ball. 



H. tuna. Articulations roundish or half kidney-shaped, one half to 

 three quarters of an inch broad ; frond flat, smooth, and thinner than 

 most species ; bright green ; somewhat flexible. (Plate VII.) 



