io6 Minnesota Algae 



tapering; apical cell showing a rotund or straight conical calyptra; cells 

 2-4 mic. in length; transverse walls sometimes showing two rows of .gran- 

 ules; cell contents densely granular, dull blue-green. 



Vermont. Charlotte. (Hosford). Connecticut. On rocks and boards, 

 in old sluiceway. Still River, New Milford. May 1892. (Setchell). Mexico. 

 Fields near Orizaba. (Miiller). 



Var. joannianiun (Kuetz.) Gomont. 1. c. 204. De Toni. 1. c. 248. 



WoUe. Fresh Water Algae. Bull. Torr. Bot. Club. 6: 283. 1879. (Ph. 

 joannianum Kg.) Collins, Holden and Setchell. Phyc. Bor.-Am. 



Fasc. 8. no. 352. 1897. 



Trichomes 5.5-7 mic. in diameter; apex of trichome often somewhat 

 gradually tapering. 



Rhode Island. Moshassuck River, near Woodlawn. April 1894. (Oster- 

 hout). New York. Old wood. Suflern. (Austin). 



210. Phormidium uncinatum (Agardh) Gomont. Essai Class. Nostocacees 

 homocystees. Morot. Journ. de Bot. 4: 355. 1890; Monogr. Oscill. 

 204. pi. 5. f. 21, 22. 1893. De Toni. Syll. Algar. 5: 250. 1907. 

 Dickie. On the Algae found during the Arctic Expedition. Journ. Linn. 



Soc. Bot. 17: 8. 1880. (O. tenuis sordida Kuetz.). Collins. Algae. 



Flora of the Blue Hills, Middlesex Fells, Stony Brook and Beaver Brook 



Reservations of the Metropolitan Park Commission, Massachusetts. 127. 



1896. Tilden. American Algae. Cent. III. no. 295. 1898. Collins, Holden 



and Setchell. Phyc. Bor.-Am. Fasc. 10. no. 452. 1898. Bessey, Pound and 



Clements. Additions to the Reported Flora of the State. Bot. Surv. Nebraska. 



5: 12. igoi. Tilden. American Algae. Cent. VI. no. 590. 1902. Setchell 



and Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 186. 



1903. Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 



7: 236. 1905. Tilden. Notes on a Collection of Algae from Guatemala. 



Proc. Biol. Soc. Wash. 21: 154. 1908; American Algae. Cent. VII. Fasc. i. 



no. 638. 1909. 



Plate V. fig. 16, 17. 



Plant mass widely expanded, adherent, thin and firm, or floating, 

 attached at base, thicker, fringed, dark green, brown or black; filaments 

 straight or somewhat flexuous; sheaths mucous, agglutinated, distinct or 

 diffluent into an abundant amorphous mucus; trichomes 6-g mic. in diameter, 

 not constricted at joints; apex of trichome briefly tapering, curved or 

 briefly spiraled, especially capitate; apical cell showing a rotund or de- 

 pressed-conical calyptra; cells 2-6 mic. in length; transverse walls frequent- 

 ly granulated; cell contents blue-green. 



Arctic Regions. Fresh water. 82° 27' N. (Dickie). Alaska. Forming 

 more or less extended blue-black layers, either submerged or on the sur- 

 face of the ground. St. Michael. (Setchell); near Iliuliuk, Unalaska; Orca. 

 (Setchell and Lawson). Greenland. (Borgesen). Maine. On stones. 

 Cromwell Harbor Brook, Bar Harbor. July 1896. (Collins). Massachu- 

 setts. In roadside pool. Valley Street. May 1908; running brook near Elm 

 Street, Medford, Middlesex Fells. (Collins). Connecticut. Forming a pur- 

 plish or copperish skin on stones in stream below dam at Moody's Pond; 



