22 THE VICTORIAN NATURALIST. 



Length of thallus, up to 36 cms. (or even more) ; breadth of 

 thallus, up to 24 cms. ; thickness of thallus, 23 jj. ; diameter of 

 cells, 4.6-10 jd. 



Habitat. — In a pool in a quarry at Burnley, associated with 

 Enteromorpha intestinalis. 



The only other fresh-water species approaching M: expansa is 

 M. rtiertihranacea, W. and G. S. West, but the Australian species 

 possesses a much larger and more expanded thallus, and the 

 cells are much more rounded and scarcely more than half the 

 size. 



Qldogonium victoriense, G. S. West (sp. n.) 



Dicecious, nannandrous, gynandrosporus ; oogonia solitary, 

 ellipsoid-globose or ellipsoid-doliform, with a superior widely 

 opened pore ; oospores exactly globose, not filling the oogonia ; 

 epispore smooth ; androsporangia 5-6 celled ; nannandria situated 

 on the supporting cells of the oogonia, furnished with a curved 

 stalk, antheridia internal and 2-cellular ; supporting cells of 

 oogonia very slightly swollen. 



Crass, cell, veget. 25-29 ^, altitude 2-3 times diameter; ciass. 

 oogonia 49 p., altitude 57 /u ; crass, oospores 39 p, altitude 39 /^ ; 

 crass, androsporangia 25-26 p., altitude 4.2-8 jx ; crass, antheridial 

 cells 7.5 jj., altitude 4.4 jx. 



Habitat. — Shallow grassy pool, Yan Yean drainage area, Octo- 

 ber, 1905. 



This species stands nearest to (E. crassiusculum, Wittr., but 

 differs in its solitary oogonia and exactly globose oospores, the 

 latter by no means filling the former. The nannandria are also 

 curved, and the antheridia are 2-celled. From OS. macrandriuin , 

 Wittr., it is distinguished by the greater thickness of its vegetative 

 cells, by the solitary oogonia with a superior pore, and by the 

 oospore not nearly filling the oogonium. It is also gynandros- 

 porous. Compare also with CE. cataracttcm, Wolle. 



With regard to my previously published list of Desmidiace^, 

 the following corrections are necessary : — (i) Professor Nord- 

 stedt's record of Australian fresh-water Algee was published in 

 1888, not "1896;" (2) " Peniimi ndgelii, Breb.," is one of a 

 group restored to the genus Netritmi ; and (3) for Eiiastrum 

 circulare, Hass., read " E. annatum, Ralfs." 



[Owing to pressure on space, the list of additional records of 

 known species is held over until next issue. — Ed. Vict. Nat.'\ 



Exchange. — The Ames Botanical Laboratory, North Easton, 

 Mass., U.S.A., is anxious to enter into correspondence and 

 exchange with plant collectors. Herbarium specimens of 

 Orchidacese and of seedling Droseras particularly required. 



