COSMARIUM. 195 



SCOTLAND.- -Grleii Dye, Kincardine (Roy Bissett). 

 Geogr. Distribution.- -Germany. 



We have never observed a Cosmarium wliicli we could 

 satisfactorily identify with C. Oligogongrus Reinsch. This 

 species appears to us to belong to the same category as 

 C. Ungerianum Xag., and should possibly be united with it ; 

 but until these two plants have been examined in detail,, it is 

 perhaps best to deal with them separately. 



182. Cosmarium Ungerianum (Xag.) De Bary. 



(PI. XCI, fig. 6.) 



Euastnun (Cosmarium) Ungerianum Xag. Gatt. einz. Alg. 1849, p. 120, 



t. 1 A,L 10. 

 Cosmarium Ungerianum (Nag.) De Bary, Coiij. 1858, p. 72: Arch, in 



Pritch. Infus. 1861, p. 732 ; Eabenh. Flor. Europ. Alg. Ill, 1868, p. 



160 ; Xordst. Bornh. Desm. 1888, p. 195 ; De Toni, Syll. Alg. 1889, p. 985. 

 Ui'sinella Ungeriana Kimtze, Rev. gen. plant, 1891, p. 926. 



Cells rather under medium size, about 1-g- times as 

 long as broad, deeply constricted, sinus linear; semi- 

 cells subtrapeziform-pyramidate, basal angles obtuse, 

 lower parts of sides strongly convex, Tipper parts 

 rapidly converging and almost straight, apical angles 

 scarcely rounded, apex almost straight; cell-wall 

 granulate, granules of unequal size, witb 4 large ones 

 on the upper lateral margins and 2 just within, with 3 

 smaller ones on the lower lateral margins and 2-3 just 

 within the basal angle, with a transverse row of 4 

 large granules across the base just above the isthmus, 

 .and one large one within the middle of the apex ; also 



with a number of smaller variably disposed granules 



/ 



in the centre of the semicells. Side view of semicell 

 subcircular. Vertical view elliptic or elliptic-oblong, 

 at each pole with 4 large granules and one median 

 small one. Chloroplasts axile, with two pyrenoids. 



Zygospore unknown. 



Length 02 ^ ; breadth 54 p. ; breadth of isthmus 

 16 p. ; thickness 32 /*. 



Geogr. Distribution.- -Germany. Sweden. Born- 

 holm. 



