72 LAURENCIACE^. v. 



am unwilling on slight discrepancies to multiply species in this genus. The pro- 

 bability of specific identity is the greater because many other Cape Alg* occur on 

 the Pacific coast of America. 



3. Laurencia obtusa, Lamour.; frond cylindrical, pinkish red or yellow, twice 

 or thrice pinnate, the pinnaj very patent ; ramuli mostly opposite (occasionally 

 alternate or irregular) patent, short, truncate. Harv. Phyc. Brit. t. 148. Kiitz. 

 Sp. Alg.p. 854. Fucus obtusus, Turn. Hist. t.21. E. Bot. t. 1201. 



Hab. Florida Keys, parasitical on corals and Algas. Key West, W. H. H., Prof. 

 Tuomei/ (33, 40, 44, &c.) Apalachicola, C apt. Pike (69). Island of St. CataUna, 

 California, Lieut. Wood, Brit. Navy. (v. v.) 



Fronds in large subglobose tufts. Stems as thick as sparrow's quill, cylindrical, 

 from one to six inches long, undivided or once or twice forked, decompound pin. 

 nate. Branches not strictly distichous, very patent, alternate or opposite, sometimes 

 three from the same level, bi-tripinnate. Pinnules opposite, alternate, or in threes, 

 cylindrical, truncate, very patent or subhorizontal, simple or with one or two pair 

 of secondary pinnules. Colour in the stem and branches generally pale waxy 

 yellow, with a reddish tinge, in the ramuli a beautiful pinky red. Substance 

 cartilaginous, firm. In drying, it adheres pretty strongly to paper. 



In the Florida specimens the ramuli are very frequently alternate, as sometimes 

 occurs in those from Europe. Perhaps the following should be considered merely 

 an exaggerated variety. 



4. Laurencia implicata, J. Ag.; frond terete, slender, much branched, between 

 pinnate and dichotomous, subfastigiate ; the lesser branches very irregular, flexu- 

 ous, patent ; ramuli cylindrical, alternate or secund, simple or forked, truncate, 

 slightly clavate. (Tab. XVIII. D.) J. Ag. Sp. Alg. 2, p. 745. L. Forsteroides, 

 Harv. in Herb. iVSS. 



Hab. Key West, W. H. H. (3G), Prof. Tuomey (23, 31, 50), Dr. Blodgett (54, 

 66.) (v. V.) 



Tifts globose, dense. Fronds 4-5 inches high, as thick as sparroAv's quill, exces- 

 sively branched from the base, the branches spreading to all sides, decompound, 

 irregularly forked, flexuous, alternately multifid above ; their lesser divisions 

 furnished with alternate or secund, cylindrical, scattered ramuli, two or three 

 lines long, simple or forked. Colour a pinky red ; orange or yellow in the 

 branches, greenish on exposure and in decay. Substance cartilaginous. It adheres 

 to paper in drying. 



Only to be known from L. obtusa (of which it may be merely a variety,) by the 

 irregular branching and much scattered, frequently secund ramuli. It seems in- 



i 



