COSMAIUTM. 259 



Cells a little smaller than the type, apices of semicells 

 less dilated, and the crenations of the margin less bold ; 

 granules very minute and not evident at the margin. 



Length 32-35 ^ ; breadth 28-30 p. ; breadth of 

 isthmus 1011 /x. 



EXGLAXD.- -Epping Forest, Essex ! 

 SCOTLAND.- -Presswhin in Cromar, Aberdeen (/u>// $' 

 . 

 \ Distribution. Galicia in Austria. 



216. Cosmarium nasutum Xordst. 

 (PL XC, figs. 9, 10.) 



Cos,-; i.-nini nasuti'in Xordst. Desm. Spetsb. 1872, p. 33, t. 7, f. 17; Boldt, 

 Desm. Gronland, 1888, p. 24 ; De Toni, Syll. Algar. 1889, p. 104S ; Borge, 

 Chlor. Xorska Fininark. 1892, p. 13 ; Sussw. Chlor. Archangel, isy-i, 

 p. 30 ; Xordst. Index Desm. 1896, p. 180 ; Sdimidle, Lappmark Siiss- 

 wasseralgen, 1898, p. 38 ; Hirn, Desm. Finiiland, 1903, p. 10 ; Larseii, 

 Freshw. Alg-. E. Greenland, 1904, p. 86. 



Crsinella nasuta Kuntze, Kevis. gen. plant. 1891, p. 925. 



Euastnim scitum West, Alg. W. Ireland, 1892, p. 141, t. 24, f. 13. 



Cosmarium ornatissimum Schmidle, Alg. Bern. Alp. 1894, p. 90, t. 6, f. 12. 



? Euastrum Langei Sclimidle, Weit. Beitr. Algenfi. Rheineb. n. Schwarz- 

 Avald. 1895, p. 79, t. 1, f. 15. [ Sclimidle' s fig. loa of the front view 

 appears to us to be a tilted or oblique view.] 



Cells small, about 1 J times as long as broad, deeply 

 constricted, sinus narrowly linear with a slightly 

 dilated extremity ; semicells trapeziform-semicircular, 

 basal angles subrectangular, sides slightly convex and 

 markedly 4-crenate (the basal crenation sometimes 

 having the appearance of a fusion of two smaller 

 crenations), apex retuse-emarginate, crenations bi- 

 granulate (sometimes almost papillate) except the two 

 apical crenations which are 3-4-granulate (or sub- 

 papillate) ; within the margin granulate, granules 

 binate (innermost often single), arranged in concentric 

 and radiating series ; in the centre above the isthmus 

 with a rounded tumour furnished with an emarginate 

 wart immediately adjacent to the isthmus. Side view 

 of semicell rectangular, at the base on each side dilated 

 and "nose-like 5 [hence specific name], apex truncate. 

 Vertical view elliptic, with a slight tumour at the 

 middle on each side, granules in transverse series, but 



