Myxophyceae 269 



cal, somewhat quadrate or shorter or longer than their diameter; basal 

 heterocysts spherical; intercalary heterocysts quadrate or cylindrical, some- 

 times in series, equalling the diameter in length, or up to seven times 

 longer than wide. 



Plate XVIII. fig. 8-10. 



Wyoming. In running, hot geyser water. October 1874. Yellowstone 

 National Park. (Kuntze). 



487. Calothrix braunii Bornet and Flahault. Revis. des Nostoc. Ann. Sci. 



Nat. Bot. VII. 3: 368. 1886. De Toni. Syll. Algar. 5: 624. 1907. 

 Setchell. Notes on some Cyanophyceae of New England. Bull. Torr. 

 Bot. Club. 22: 426. 1895. Collins, Holden and Setchell. Phyc. Bor.-Am. 

 Fasc. 3. no. 112. 1895. Tilden. American Algae. Century III. no. 286. 

 1898. Setchell. Notes on Cyanophyceae. — III. Erythea. 46. 1899. 



Setchell and Gardner. Algae of Northwestern America. Univ. Calif. Pub. 

 Bot. i: 198. 1903. Collins. Phycological Notes of the late Isaac Holden. 

 — II. Rhodora. 7: 237. 1905. 



Plate XVIII. fig. II. 



Plant mass caespitose, velvety, blue-green; filaments 9-10 mic. in 

 diameter, .5 mm. in length, densely crowded, parallel, straight, curved 

 and thickened at the base; sheaths narrow, close, uniform, colorless; trich- 

 omes 6-7 mic. in diameter, equal, tapering into a very long hair, often 

 constricted at joints; cells a little shorter than their diameter; hetero- 

 cysts basal. 



Massachusetts. Growing on stones in a small brook. Sharon; forming 

 extended patches on rounded stones in a small rivulet, Cataumet. (Setch- 

 ell). Connecticut. On stones in shallow water. Bridgeport. October 1893; 

 forming a coating on stones, side stream of Pequonnock River, below Fac- 

 tory Pond Dam, October. (Holden). Washington. On dead floating 

 stems of S c i r p u s. Lake' Washington, Seattle. July 1897; on pebbles at 

 edge of Lake Union, Seattle, June 1897. (Tilden). 



488. Calothrix parietina (Naegeli) Thuret. Essai Class. Nostochinees. Ann. 



Sci. Nat. Bot. VI. i : 381. 1875. Bornet and Flahault. Revis. des Nos- 

 toc. Ann. Sci. Nat. Bot. VII. 3: 366. 1886. De Toni. Syll. Algar. 5: 

 621. 1907. 

 WoUe. Fresh Water Algae. II. Bull. Torr. Bot. Club. 6: 138. 1877. 

 (Mastigonema caespitosum Kg.); Fresh Water Algae. 1. c. 6: 

 284. 1879, (Schizosiphon crustiformis Naeg.). Farlow. Marine 

 Algae of New England. 40. 1881. WoUe. Fresh-Water Algae U. S. 237, 

 245. pi. 173. f. 2, 3; pi. 176. f. S; pl- 178. f. 1-3; pl. 205. f. 6, 7. 1887. (Calo- 

 thrix gracilis Rab., Isactis caespitosa (Kg.) Wolle, including f. 

 tenuior viridis Rab.). Wolle and Martindale. Algae. Britton's 

 Catalogue of Plants found in New Jersey. Geol. Surv. N. J. 2: 603. 1889. 

 Collins, Holden and Setchell. Phyc. Bor.-Am. Fasc. i. no. 12. 1895. Til- 

 den. American Algae. Cent. I. no. 65. 1894. (Porphyrosiphon no- 

 tarisii Kg.). Cent. II. no. 164. 1896. Collins. Algae.^ Flora of the Blue 

 Hills, Middlesex Fells, Stony Brook and Beaver Brook Reservations of the 



