ALGAE OF THE PEIBILOF ISLANDS. 595 



Islands, available to the writer in all three collections, viz, from the collection sent to 

 Professor Baton in 1877 by the Alaska Commercial Company, by the Albatross expe- 

 dition of 1895, and also by a considerable number of specimens in the collection pro- 

 cured by President Jordan. It seems to the writer that the chief danger in connec- 

 tion with this species might possibly be in confusing it with D. middendorfii Eupr., as 

 the Greely and Snodgrass specimens are generally proliferate from the midrib and 

 often fasciculately so. The lateral nerves, however, are much more prominent than 

 seems to be the case in D. middendorfii. 



Delesseria spinulosa (Rupr.) J. Ag. 



D. beringiana, var. spinulosa Euprecht, Tange Ooh. ; 244, 1851. 



Euprecht's reference is all that is known concerning the occurrence of this species 

 at St. Paul Island. It grows upon the blade of Agarum turneri. 



Delesseria complauata Eupr. Euprecht, Tange Ooh. ; 245, 1851. 



Grows on Ptilota asplenioides, at St. Paul Island, according to Euprecht. 

 Delesseria juergensii J. Ag. Parlow, Proo. Amer. Acad., 21; 473, 1886. 



Farlow says (1. c.) that this species occurs in the collections sent to Professor 

 Baton in 1877. 



Constantinea rosa marina (Gmel.) P. and E. Euprecht, Tange Ooh.; 232, 1851. Kjellman, Bering- 

 shafvets Algflora; 30, 1889. 



This interesting form occurs from St. Paul Island, in the collection sent to Pro- 

 fessor Eaton, The specimens do not answer exactly to the description in J. Agardh's 

 " Ei)icrisis," but they do answer to Gmelin's figure. (Bering Island.) 

 Amphiroa cretacea (P. and R.) Aresoh. Kjellman, Beringshafvets Algflora; 20, 1889. 



Although Ball (1875, p. 166) speaks of a Coralline zone about the islands, the 

 collections contain only few and imperfect specimens of these forms. Consequently 

 it has been impossible to give any satisfactory account of the species of this family. 

 The present determinations must be looked upon as unsatisfactory, but as the best at 

 present possible. Only two specimens of A. cretacea are available to the writer, and 

 these are both imperfect and sterile. (Port Clarence; St. Lawrence Island; Bering 

 Island,) 

 Arthrooardia frondescens (P. and E.) Aresoh. Kjellman, Beringshafvets Algflora; 20, 1889. 



Only two or three fragments are available, consequently the exact determination 

 must remain in doubt. (Bering Island.) 



Lithophyllum . 



Several specimens of a species of this genus occur on the specimens of Arthro- 

 cardia mentioned above, but they are all sterile. 



Lithothamnion . 



Several specimens of this genus are present in the collection obtained by Presi- 

 dent Jordan, but they are young and sterile, so th^-t no certain disposition can be made 

 of them. They grew upon pebbles. 



University of California, 



Berkeley, Gal., December 9, 1898. 



