Algae. 357 



II. Cell Structure and Zoospore Formation in Pediastruni 

 Bovyanian (Turp.) Menegh. (Annais Bot. XXX. N« 119. p. 467- 

 479. 1 pl. and ligs. July 1916.) 



The youngest cells of this plant (one of the Hydrodictyaceae) 

 are uninucleaie, and each contain one pyrenoid (rarely two or 

 three). INlature cells contain four or eight nuclei and one to three 

 pyrenoids. The nuclei increase in number by simultaneous division 

 is always a multiple of two. In structure the resting nucleus differs 

 but little from the nucleus of the higher plants. The pyrenoids are 

 homogeneous in structure and surrounded by curved starch plates. 

 Previous to zoospore formation there is a period of active simulta- 

 neous nuclear division resulting in 16, 32, 64, or 128 nuclei within 

 the cell. The zoospores are formed by cleavage. The cleavage is 

 progressive, forming first multinucleate protoplasts and later uni- 

 nucleate ones. The pyrenoid disappears previous to or during the 

 first stages of cleavage. After cleavage is completed the nuclei 

 become dense, and the line of demarcation between the protoplasts 

 disappears, reappearing shortl}^ before the zoospores are liberated. 



E. S. Gepp. 



Takeda, H., Dvsmorphococcus variahüis, gen. et sp. nov. (Annais 

 Bot. XXX. N0^117. p. 151 — 156. figs. Jan. 1916.) 



This new unicellular flagellate alga belongs to the Phacoteae, a 

 subfamily of the Volvocaceae. It was collected with other algae in a 

 small pond in Richmond Park. Cell floating free; protoplast 

 pyriform, bearing a pair of equal flagella nearly twice as long as 

 itself, and living free within a hard, brittle, brown spherical Shell 

 pierced with two apertures for the flagella; chromatophore Single, 

 green, urceolate; Stigma small, parietal; nucleus almost central. 

 Propagation unknown. E. S. Gepp. 



Takeda, R., On Carteria Fvitschii sp. n. (Annais Bot. XXX. N« 119. 

 p. 369-372. figs. July 1916.) 



This new flagellate fresh-^vater alga was found at Keston, 

 Kent. in May 1915, and was cultivated for six months. It has a 

 remarkably thick outer cellmembrane and also a much-developed 

 gelatinous inner cell-wall, the unevenness of which often prevents 

 the protoplast from conforming with the contour of the cell. It is a 

 small ovoid organism with four radiating flagella, and contains a 

 Single chromatophore, a conspicuous pj'^renoid, a stigma, two con- 

 tractile vacuoles, and a nucleus. It has a forward or a slower back- 

 ward movement at will; and it shows an affinity with C. multifüis 

 (Fes.) Dill. It is reproduced by longitudinal division of the mother- 

 cell in one or two directions. E. S. Gepp. 



Takeda , H., Scourfieldia cordifonnis, a new Chlamydomonad. 

 (Ann Bot. XXX. N^ 117. p. 157-159. figs. January 1916.) 



This alga, found in a Sphagimm marsh, at Keston, Kent, 

 diff'ers from Sc. compJauata in having an obovate side profile. It is 

 very small, heart-shaped in front view, slightly emarginate at apex 

 and provided with two long flagella four times the length of the 

 cell; chromatophore Single, green, homogeneous, subcampanulate; 



