Myxophyceae 187 



Species not well understood 



A. azollae 

 A. confervoides 

 A. cupressophila 

 A. gelatinosa 

 A. subrigida 



347. Anabaena variabilis Kuetzing. Phyc. Gen. 210. 1843. Bornet and Fla- 

 hault. Revis. des Nostoc. Ann. Sci. Nat. Bot. VII. 7: 226. 1888. De 

 Toni. Syll. Algar. 5: 437. 1907. 

 WoUe. Fresh-Water Algae U. S. 287. pi. 198. f. 29-32. 1887. Bennett. 

 Plants of Rhode Island. 114. 1888. (Sp h a e r o z y g a polysperma 

 Rab.). WoUe and Martindale. Algae. Britten's Catalogue of Plants found 

 in New Jersey. Geol. Surv. N. J. 2: 607. 1889. Anderson and Kelsey. 

 Common and Conspicuous Algae of Montana. Bull. Torr. Bot. Club. 18: 

 144. 1891. Setchell. Notes on some Cyanophyceae of New England. Bull. 

 Torr. Bot. Club. 22: 429. 1895. Collins, Holden and Setchell. Phyc. Bor.- 

 Am. Fasc. 3. no. 107. 1895. Tilden. American Algae. Cent. II. no. 169. 



1896. Richter. Siisswasseralgen aus dem Umanakdistrikt. Bib. Bot. 7: 

 Heft. 42. 5. 1897. Setchell. Notes on Cyanophyceae. III. Erythea. 7: 

 SI. 1899. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. is. no. 

 709. 1900. Collins. Preliminary Lists of New England Plants. V. Marine 

 Algae. Rhodora. 2: 41. 1900. Tilden. Collection of Algae from the Hawai- 

 ian Islands. Hawaiian Almanac and Annual for 1902. 112. 1901; American Al- 

 gae. Cent. V. no. 483. 1901; American Algae. Cent. VI. no. 678. 1902; Algae 

 Collecting in the Hawaiian Islands. Postelsia. i: 168. 1902. Setchell and 



Gardner. Algae of Northwestern America. Univ. Calif. Pub. Bot. i: 191. 1903. 

 Collins. Phycological Notes of the late Isaac Holden. — II. Rhodora. 7: 223. 

 190s. Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 2S. no. 1209. 

 1905. Lemmermann. Algenfl. Sandwich-Inseln. Bot. Jahrb. 34: 622. 190S. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. 31. no. 1507. 1908. 

 (A. variabilis brachyspora Collins). 



Plate IX. fig. 9. 



Plant mass gelatinous, spreading on damp soil or floating free, dark 

 green; sheaths usually not present; trichomes 4-6 mic. in diameter, flexuous, 

 slightly constricted at joints; apical cell obtuse conical; cells 2.S-6 mic. in 

 diameter, somewhat quadrate; heterocysts 6 mic. in diameter, 8 mic. in 

 length, spherical or oval; gonidia 7-9 mic. in diameter, 8-14 mic. in length, 

 oval, truncate at the apices, numerous in catenate series, remote from 

 heterocysts, developed centrifugally; wall of mature gonidium smooth, 

 yellowish brown. 



Greenland. Umanak. (Vanhofifen). Maine. Among various floating 

 Algae in a warm pool above high water mark. Ragged Island, Casco Bay. 

 July 1908. (Collins). Rhode Island. Spectacle Pond. (Bennett). Forming 

 a brownish or bluish green, gelatinous layer on the floating leaves of 

 Ruppia maritima, in brackish water. Watch Hill Pond, Watch Hill. 

 September 1894. (Setchell). Connecticut. Fresh Pond. (Collins, Holden). 



