214 BRITISH DESMIDIEjC. 



40. S. rugulosum (Breb.) ; segments elliptic, denticulate at their 

 sides ; end view triangular, with the angles broadly rounded and 

 denticulate. 



Euastrum, No. 9, Bailey, American Journ. of Science and Arts, v. 41. p. 296. 



t. l.f. 9 (1841). 

 Staurastrum rug%dosi(m, Brebisson, in lit. cum icone (1846). 



West Point, New York, Bailey. Falaise, Brebisson. 



Tab. XXXV. fig. 19. from drawings by M. de Bre'bisson : a. front view; 

 b. end vicAv. 



41. S. scabrum (Breb.); segments elliptic, scabrous; end view tri- 

 angular, fringed with minute emarginate spines. 



Sfaurastrum scabrum, Brebisson, m lit. cum icone (1846). 

 Falaise, Brebisson. 



Tab. XXXV. fig. 20. from drawings by M. de Brebisson : a. front view ; 

 b. end A-iew. 



42. S. bacillare (Breb.) ; frond smooth ; processes capitate ; end view 

 with three to five capitate rays or processes. 



Binatella bacillaris, Brebisson, Alg. Fal. p. 66 (1835). 

 Staurastrum bacillare, Breb., Meneghini, Synop. Desmid. in Linneea 1840, 

 p. 228. Brebisson, in lit. cum icone. 



Falaise, Brebisson. 



Frond smooth ; processes in front view stout, divergent, each terminated by 

 a round knob ; end view three- to five-rayed, the rays capitate in the same 

 manner as in the front view. 



A remai'kable and very distinct species. 



Tab. XXXV. fig. 21. from drawings by M. de Brebisson : a. front ^-iew of 

 frond ; b, c, d. transverse views. 



4.3. S. Capitulum (Breb.) ; segments quadrate, sinuated on each side, 

 prominences rough ; end view triangular, with broadly rounded 

 angles. 



Staurastrum Capitulum, Brebisson, in lit. cum icone (1836). 

 Falaise, Brebisson. 



Frond quadrilateral, nearly twice as long as broad ; constriction shallow ; 

 the segments have two rounded prominences on each side and a small semi- 

 circular sinus between them ; these prominences are rough with minute gra- 

 nules, which give them a crenate appearance. End margin straight. End 

 view triangular, the angles broadly rounded ; sides nearly straight, bat each 

 slightly constricted at the middle. 



Tab. XXXV. fig. 25. from drawings by M. de Brebisson : a. front view of 

 frond ; 6. end view. 



