92 PROCEEDINGS OF THE AMERICAN ACADEMY. 



Typical specimens of this fine species were collected, some more 

 than 12 cm. long. The species has a characteristic rusty-brown color 

 and is coarser than P. Pavonia. In the median portion the frond 

 has usually ten layers of cells, 80 X 40 /i in section, and a single layer 

 of cortical cells, 14 X ^ y- The very large oosporangia vary from 

 110-125 /x X 70-84 /x. 



Sargassum, Ag. 



S. crMOSUM, Ag. Spec. i. 20 (1821) ; J. Ag. Sp. Sarg. Austr. 

 100 (1889). — Albemarle Isl. : Tagus Cove and Turtle Pt., March, 

 1899, Snodgrass & Heller. "Wenman Isl. : Dec. 1898, Snodgrass & 

 Heller. Further distrib. warmer Atlantic coasts of Asia and Africa. 



In the determination of this species I have followed J. Ag. 1. c. 

 (1889) and the Albemarle and Wenman Island specimens seem to me 

 to belong to S. cyniosum as that species is limited by J. Agardh. 

 The species has, however, been variously interpreted by different writers. 



S. GALAPAGENSE, Grunow in Piccone (1), 48, t. 1. — Chatham Isl. : 

 Marcacci, ace. to Piccone, 1. c. Endemic. 



S. GALAPAGENSE, var. SETiFOLiA, Grunow in Piccone (1), 48, t. 2, 

 f. 1, 2 (1886). — Albemarle Isl.: Tagus Cove and Turtle Pt., Peb. 

 1899, Snodgrass & Heller. Chatham Isl. : March, 1884, Marcacci, 

 ace. to Piccone, 1. c. Endemic. 



As is remarked by J. Agardh, 1. c, 122, this variety is closely related 

 to S. jyilidiferum (Turn.) Ag., of California and Japan, but not to S. 

 acinaria (Turn.) J. Ag., as suggested by Grunow. 



? S. GRAMiNiFOLiDM, J. Ag. Spec. i. 103 (1848). Fucxis gramini- 

 folu/s, Turn. Hist. Fuc. PI. 210 (1819). — Wenman Isl.: Snodgrass 

 & Heller. Further distrib. China Sea. 



To this species is referred with much doubt a single specimen of a 

 Sargassu7n with the upper fructiferous portion only. The receptacles 

 are racemose, the conceptacles contain antheridia and oogonia, and the 

 leaves are long, narrow, serrate, with but few cryptostomata. 



S. lendigerum, var. foliosa, Grunow in Piccone (1), 49. — Chatham 

 Isl. : March, 1884, Marcacci, ace. to Piccone, 1. c. 



S. LENDIGERUM, var. FURCiFOLiA, Grunow, 1. c. 50. — Chatham Isl. : 

 March, 1884, Marcacci, ace. to Piccone, 1. c. 



Of the var. foliosa, Grunow described two forms, suhdelicatula and 

 rigidiuscida and of xar. fta'cifoUa a iormu. denticulata. J. Agardh, 1. c. 



