116 DICTYOTACEiE — Potctaeia. iv. 



obovate, much attenuated at tlie base. Harv. Phyc. Brit. t. 228. /. Ag. Sp. Alg. 

 vol. \,p. 73. Phycolapathum plantagineum, Kiitz. Sp. Alg. p. 483. 



Hab. On stones and Algte between tide-marks. Annual. Summer. Prince 

 Edward's Island, Dr. Jeans. Boston Harbour, G. B. Emerson, Esq. (v. v.) 



Tufted. Fronds from 6 to 12 inches long, an inch to an inch and half in breadth 

 in the widest part, generally blunt, obovate or cuneate, tapering considerably to the 

 base from near the middle of the membrane. The substance is thicker and more 

 coriaceous than in P. latifolia and the colour always darker. But specimens occur 

 which are almost intermediate in character between the two. There is also danger 

 of confounding P, plantaginea with Laminaria Fascia, which has a very similar 

 appearance. 



Pun'CTARia latifolia, Grev. ; frond pale olive green, thickish, membranaceous, soft 

 and tender, oblong or obovate, suddenly tapering at the base. Harv. Phyc. Brit., 

 t. 8. J. Ag. Sp. Alg. vol. I, p. 73. Phycolapathum debile, Kiitz. Sp>. Alg. 483. 



Hab. On stones and Algte between tide-marks. Annual. Summer. Halifax, 

 W. H. H. Boston Harbour, G. B. Emerson. Flushing Bay, Long Island, Prof- 

 J. W. Bailey and Mr. Hooper. Fort Hamilton, N. Y. Mr. Hooper, &c. (v. v.) 



Tufted. Fronds eight to twelve inches long, and from one to three inches wide 

 in the broadest part, oblong or obovate, or somewhat ovate, generally obtuse, and 

 suddenly tapering at the base into a short cuneate stem, a line or two in length. 

 The margin is undulate, sometimes much crisped and curled. The substance is 

 thin, membranaceous, soft, and almost gelatinous to the touch when young, at which 

 time it is clothed with pellucid hairs ; afterwards it is more rigid, and at length so 

 coarse that it will not adhere to paper Avhen drying. The colour, when young, is an 

 extremely pale olive, inclining to green, and specimens are often found that retain 

 this colour at their full size, but now and then others accompany them in which the 

 colour is much darker. These approach P. plantaginea, and are then only to be 

 known by the less tapering base. I retain the three species as published by Greville; 

 though I admit that it is sometimes difficult to distinguish between them in every case. 

 There are three principal typical forms, and a number of intermediate links. The 

 present is much the commonest on the American shore, and after it that called P. 

 tenuissima. I shall not be surprised if future botanists, when the rage for species- 

 making has exhausted itself, and the tide sets in an opposite direction, shall re-unite 

 these three under the old name plantaginea. 



