58 LAMINARIACEAE 
pinnatifid thallus. It bears little resemblance to the youngest 
stage of the Peruvian plant that we have seen (PLATE 15) and still 
less to the older forms and we think it probable that it represents 
a true Ecklonia as has been generally supposed. Laminaria 
` biruncinata is figured as having the surface of its lamina covered 
with teeth and difform processes, while Eisenia Cokeri is free from 
such outgrowths if one may except rarely occurring submarginal 
teeth. 
PLATE 14, FIGURE A. Eisenia Сокет 
Photograph of a group of plants collected on the beach of San Lorenzo Island, 
near Callao. (Photograph from Dr. Cok 
PLATE 15. Eisenia Cokeri 
Photograph of a young нар Опа PANE дексе 71) collected 
on beach of San Lorenzo Island, a li of the natural dimensions. 
PLATE 16, Eisenia Cokeri 
Photograph of a fragment (from liquid preservative—Coker 28) collected at 
La Punta, region of Callao, showing one of the supercrural expansions and the basal 
parts of the sporophyls springing from it; about two fifths of the natural dimensions, 
PLATE 18, FIGURE A. Eisenia Cokeri 
A photograph, taken by Dr. Coker, showing beach drift on Sechura Bay. This 
22 i said by him to consist almost exclusively of the kelp here described as Eisenia 
okeri. 
An undetermined “Laminaria” from Ancón near Callao is 
listed by Piccone (Alg. Vettor Pisani 37. 1886). 
LESSONIA Bory, Dict. Class. Hist. Nat. 92-321; 1820 
LESSONIA NIGRESCENS Bory, loc. cit. 322; Voy. Coquille, 
Bot. Crypt. 80. 1827; pl.5. 1828. Post. & Rupr. 
Шиві. Alg. 3. pl. 4. 1840. Skottsberg, 
Schwed. Sudpol.-Exp. 4°: 69-72. 
f. 81-88. 1907 
Pescadores Islands, region of Апсбп, Feb. 12, 1907, Coker 
09150 p.p.; Chincha Islands (“ common, with short stems attached 
to vertical surfaces of rocks in surf by stout tangled holdfasts’’); 
June 18, 1907, Coker 107 and 09612 (PLATE 17). 
The plants reach a length of a little more than a meter and are 
4-6 times dichotomous; the main stipe is 0. 75-1.5 cm. in diameter, 
is strongly flattened from the base and the bases of originally 
