OF ARTS AND SCIENCES. 235 



XX. 



ON SOME ALG^ NEW TO THE UNITED STATES. 



By W. G. Farlow. 



Presented May 9, 1877. 



The present paper is a supplement to one presented to the Academy, 

 March 9, 1875 ; and our object is to com[)lete, as far as possible, the 

 list of marine algiB found in the United States. We include a number 

 of species which were referred to in a paper in the " Report of the 

 United States Fish Commission" for 1875, which was intended to 

 serve as a guide to the collection of algse in the Government Building 

 at the Centennial Exhibition. Some species of New England, which 

 are soon to be described at length in another publication, are here 

 mentioned only by name. 



Of the species added to our marine flora, a number were collected at 

 Key West and the Tortugas by Mr. F. W. Hooper, in the winter of 

 1876. New Californian species have been received from Dr. Anderson, 

 of Santa Cruz; Mr. Cleveland; Mr. Hemphill, of San Diego; and 

 Miss Lennebacker, of Santa Barbara. Several interesting forms were 

 collected by Dr. Edward Palmer at the island of Guadeloupe and in 

 the vicinity of San Diego, and Prof. D. C. Eaton, of New Haven, has 

 kindly communicated species from both east and west coasts. 



FLORIDE^. 



Dasya subsecunda Suhr. K.tz. Tab. Phyc, V. XIV., PI. 78 a. b. 

 D. CalUthamnion Harv. Farlow, Proc. Am. Acad., 1875, San Diego, 

 Cleveland ; Santa Barbara, Dr. Dimmock. This minute species, which 

 is not uncommon in Southern California, has the habit of C. Wurde- 

 manni Bail., but the ramuli are robust and more or less secund, while 

 in C. Wvrdemanni they are attenuated and dichotomous, bi-anching at 

 wide angles. We formerly erroneously referred this species to D. Cal- 

 Uthamnion Harv., being led to that conclusion by tlie fact that a cross- 

 section of the stem showed four cells around a central cell, as was also 

 the case with an authentic specimen of D. CalUthamnion Harv. Far- 



