92 ZYGOPHYCEiE. 



Plate XXXVI. fig. 1. a, sterile cells X 200 ; 5, conjugating cells with 

 zygospores X 200 ; c, sterile cells of inflated form X 200 ; d, conjugating 

 cells with zygospores X 200; e, f, g, outlines of zygospores X 400. 



Spirogyra longata. Vauch. 



Sterile cells with the ends truncate, 3 to 8 times as long as 

 broad, chlorophyll bands single or rarely two, making 1 to 

 6 turns of a spiral. 



Spores 1^ to 2 times as long as broad, membrane even, chest- 

 nut colour. 



S poriferous cells swollen and usually longer than the spore. 



SIZE. Cells -024--03 mm. diarn. Zygospore -04--07 x '03 mm. 



Cleve Monog. Zygn. p. 20, t. 3, f. 8-10; t. 4, f. 1-7 ; t. 10, 

 f. 11-13. 



Conjugata longata, Vauch. Conf. p. 71, t. 6, f. 1. 



In pools and ditches. 



far. a. c omniums. 



Sterile cells 3 to 8 times as long as broad. 



Spirogyra longata, Kutz. Tab. v. t. 20, f. 1. Rabh. iii. 238. 

 Petit Spirogyra t. 5, f. 4, 5. 



Zygnema commune, Hass. Alg. t. 28, f. 5, 6. Ann. Nat. Hist, 

 x. (1842) p. 39. Jenner Fl. Tunb. Wells, 180. 



Zygnema (Estivum, Hass. Alg. t. 28, f. 3, 4. Ann. Nat. Hist, 

 xi. (1843), p. 433. Jenner Fl. Tunb. Wells, 180. 



Zygnema angulare, Hass. Alg. t. 34, f. 1, 2. Jenner Fl. 

 Tunb. Wells, 180. 



Zygnema angidatum, Hass. Ann. Nat. Hist. x. (1842) p. 41, 



Zygnema reversum, Hass. Alg. t. 33, f. 3. 



Zygnema alternatum, Hass. Alg. p. 154. 



Zygnema mirabile, Hass. Alg. t. 35, f. 1-3. 



Spirogyra communis, Kutz. Tab. v. t. 19, f. 4. Petit Spiro- 

 gyra t. v. f. 1-3. 



Rhynchonema angulare, Kutz. Tab. v. t. 34, f. 1. Rabh. iii. 

 232. l 



Rliynclwnema reversum, Kutz. Rabh. iii. 232. 



Spirogyra subtilis, Kutz. Tab. v. t. 19, f. 5. 



Spirogyra mirabilis, Kutz Sp. p. 438. Petit Spirogyra p. 14, 

 t. 3, f. 3-4. 



Conjugata longata, Gray Arr. i. 279 (?) 



var. (3. turpis. 



Sterile cells abbreviated. 



Zygnema malformatum, Hass. Alg. t. 30, f. 1, 2. Ann. Nat. 

 Hist. x. (1842) p. 39. Jenner Fl. Tunb. Wells, 180. 



Zygnema catceneforme, Hass. Alg. t. 30, f. 3, 4. Ann. Nat. 

 Hist. x. (1842), p. 39. 



Zygnema abbreviatum, Hass. Alg. t. 34, f. 4. 



