118 COLLIXS AND HEEVEY. 



3. Frond decumbent, rooting, densely matted. 1- L- perforata. 



3. Frond erect. 4. 



4. Outline of frond and of main divisions narrowly pyramidal. 5. 



4. OutUne broader. 6. 



5. Slender, 3 or 4 cm. high. 5. L. obtusa var. gelatinosa. 



5. Stout, 1-2 dm. high. 6. L. paniculata. 



6. Branching mostly opposite or whorled. 5. L. obtusa. 



6. Branching subdichotomous, corymbose. 4. L. cervicornis. 



1. L. PERFORATA Montagne, 1860, p. 155; Kiitzing, 1865, p. 18, 

 PI. XLIX, figs, c^g; P. B.-A., No. 1889. Bailey's Bay, Jan., Harris 

 Bay, Jan., Nov., Gravelly Bay, Oct., Hervej-; Tucker's Town, May, 

 South Shore, Aug., Collins. This species occvu^ not uncommonly in 

 caves and potholes, where it forms dense matted masses, the filaments 

 adhering to the rock and to each other by numerous holdfasts. The 

 surface of the mass sometimes has an iridescence of remarkable 

 brilliancy, chieflj' in metallic blues and greens. The iridescence is on 

 the upper surface only, and persists for a short time after the plant is 

 taken from the water. 



2. L. PoiTEi (Lamour.) M. A. Howe, 1905, p. 583; L. tuberculosa 

 J. G. Agardh, 1852, p. 760; P. B.-A., No. 1937. L. gemmifera Harvey, 

 1853, p. 72, PI. XVHI. B.; Fucus Poitd Lamouroux, 1805, p. 63, PL 

 XXXI, figs. 2-3. Harrington Sound, Farlow; Cooper's Island, a 

 slender form, Wadsworth; Heron Bay, April, Hervey; Fairyland, 

 July, Collins. In warm shallow water, where it forms loose-ljing 

 masses in warm weather. L. tuberculosa has been described by J. G. 

 Agardh as "fronde compressa distiche decomposito-pinnata," but it 

 may well be that the compression and distichous branching in Agardh's 

 plant are due to the manner of preparation; the Bermuda plant has 

 no such characters. 



3. L. PAPiLLOSA (Forsk.) Greville, 1830, p. LII; P. B.-A., No. 1936; 

 Fwnis papillosus Forskal, 1775, p. 190. Castle Harbor, Farlow; 

 Harris Bay, Jan., Heron Bay, April, Hervey; Jew's Bay, July, 

 Cooper's Island, Harrington Sound, Aug., Collins. Quite common 

 and usually easily recognizable. 



4. L. CERVICORNIS Harvey, 1853, p. 73, PL XVHI. C; P. B.-A., 

 No. 2187. Wadsworth, No. 19; iSIiss Wilkinson; Cooper's Island, 

 April, Aug.; dredged in 4 m., Dec, Collins; Buildings Bay, April, 

 St. David's Island, May, Hervey. This species appears to be Uttle 

 known to European botanists; De Toni, 1903, p. 781, gives it as a 

 synonjTn under L. implicata, but it is certainly not the L. implicata 

 of Harvey, 1853, p. 72, PL XVHI. D., fide authentic specimens. L. 



