THE ALGAE OF BERMUDA. 119 



cervicornis has a frond of rounded outline, branching subdichotomous, 

 distant below, increasingly close upward; all branches, long or short, 

 are of about the same diameter, about that of the main axis of a 

 frond of L. obtusa, medium size. Proliferous ramuli, very short, 

 may be abundant or nearly or quite wanting. It is found in rather 

 sheltered stations, the color a somewhat deep and translucent red 

 in the living plant, growing darker in the mounted specimen. It 

 usually adheres fairly well to paper. 



5. L. OBTUSA (Huds.) Lamouroux, 1813, p. 42; Harvey, 1846-51, 

 PI. CXLVIII; P. B.-A., No. 2092; Fucus ohtusus Hudson, 1798, p. 

 586. A very common and variable species, occurring nearly every- 

 where in quiet water, and often in somewhat exposed places, and 

 dredged to a depth of 18 m. The genus Laurencia is very puzzling; 

 though typical forms can be found of all the species, intermediate 

 forms are equally common, and it is very difficult to draw any sharp 

 lines. Of what may be considered the typical form of L. obtusa there 

 are two varieties, differing sharply in color, but not otherwise; one is 

 reddish or yellowish brown, lighter where exposed to sunshine, darker 

 below; the other a light, glaucous blue-green. They grow in similar 

 stations; often, as in the lower part of Harrington Sound, both are 

 found together, but as separate individuals or tufts; we have seen no 

 intermediate forms under these conditions. ^^ Beside the typical form, 

 two varieties may be noted. 



Var. GRACILIS Kiitzing, 1865, p. 20, PI. LIV, figs, c and d; L. dasy- 

 phylla Kemp, in herb. A delicate, soft and slender form. 



Var. GELATiNOSA (Desf.) J. G. Agardh, 1852, p. 751; P. B.-A., No. 

 1888; Fucus gelatinosus Desfontaines, 1798, p. 427. Mrs. Hastings; 

 Spanish Rock, Jan., Gravelly Bay, March, Dec, Hervey. Tetraspores 

 in Jan. A low and slender form of exposed rocky shores; in spite of 

 its name it is firmer and less adherent to paper than L. obtusa, 

 tj'pical. In connection with L. obtusa we have found forms near to 

 L. setacea Kutzing, 1848, p. 854; L. intricata Kiitzing, 1865, PI. LXI, 

 figs, a-c,^^ but they shade into the typical L. obtusa so plainly, and in no 



15 It is of interest to note that practically the same forms occur at Naples; 

 see Falkenberg, 1901, p. 247. "Um Neapel, wo die Pflanze das ganze Jahr 

 hindurch zu den gemeinsten Formen gehort, kommt sie in zwei Varietateu 

 vor, welche, im tibrigen gleich, durch ihre Farbmig sich wesentlich unter- 

 soheiden, die eine ist gelbrothlich, die andere griinlich. Beide Formen treten 

 gesondert in unregehnassig durch einander gewirrten Rasen an den gleichen 

 Standorten auf." 



16 L. intricata Lamouroux, 1813, p. 43, PI. IX, figs. 8-9, is nomen nudum, 

 hence Kiitzing's name of 1848 has priority. 



