68 FUCACE^.— Fucus. iv. 



Sect. 1 . FucoDiuM, J. Ag. Frond compressed or subterete, without a midrib. 



1. Yucvs fastigiatiis, J. Ag. ; frond terete below, compressed above, linear, very- 

 narrow, many times dichotomous, fastigiate ; the angles rounded and branches 

 widely spreading ; air-vessels none ; receptacles terminal, simple or forked, oblong. 

 J. Ag. Sp. Alg. vol. 1, Sp. 203. KUtz. Sp. Alg. p. 591. Fucus furcatus, Harv. in 

 Bot. Beechey, p. 163 (not of Ag.) (Tab. III. A.). 



Hab. On rocks within tide marks (probably above half tide level). Monterey, 

 Douglas! Coulter! St. Francisco, Capt. Wilkes! (v. s. in Herb. T.C.D.) 



Root a conical disc. Frond rising with a short terete stem, which becomes forked 

 at about half an inch from the base. The two primary divisions are generally much 

 divaricated, making a very wide angle, and the frond is repeatedly forked at 

 intervals of from half an inch to an inch, till it attains the length of six or eight 

 inches. There are frequently as many as twelve furcations in plants of this size. 

 The lower parts of the stem are from one to two lines in diameter ; the upper are 

 gradually more and more slender, and at length the extreme forkings are often not a 

 quarter line in breadth. The branches spread widely, so that the general outline of 

 a frond is much broader than its length. There are no air-vessels. The branches 

 are of nearly equal height, and in full grown specimens their tips are almost all 

 enlarged into oblong or fusiform, simple or forked, tuberculated receptacles. 

 Spores two in each perispore, a great number of which are attached to the walls of 

 the spore-cavity. 



My description and figure are made from Dr. Coulter's specimens ; those brought 

 by Douglas and Wilkes (that I have seen) being of smaller size, and apparently 

 gathered in shallower water. This species is, in many respects, allied to the Euro- 

 pean F. canaliadatus, and probably occupies similar ground, near high-water mark. 

 My specimen from Douglas has altogether the dwarfed appearance which indicates 

 such a locality. 



2. Fucus nodosus, Linn. ; frond compressed, coriaceous, subdichotomous ; the 

 branches linear, somewhat pinnated, attenuated at the base, remotely toothed, here 

 and there swelling into oblong air-vessels ; receptacles lateral, globose, stalked, 

 springing from the axis of the marginal teeth. J. Ag. Sp. Alg. vol. 1, p. 206. 

 liar. Phyc. Brit. t. 158. E. Bot. t. 570. Turn. Hist. t. 91. Ozothallia vulgaris, 

 Dm. — Kiltz. Sp. Alg. p. 591. Physocaulon nodosum, Kiltz. Phyc. Gen. p. 352. 



Hab. On submarine rocks, between tide-marks. Abundant on the Atlantic shores 

 of North America from Halifax to New York. Newfoundland, De la Pylaie. 



(V. V.) 



Fronds densely tufted, from one to three or four feet long or more, compressed, 

 linear, much branched, more or less pinnate ; the branches long and subsimple, 



