128 BRITISH DESMIDIE.E. 



12. S. teliferum ; segments reniform, bristly ; end view trian- 

 gular, with concave sides and broadly-rounded bristly angles. 



Dolgelley and Penzauce, J. R. Ambleside, 3Ir. Sidehotham. Hadlow 

 Down near Mayfield, and several other stations in Sussex, Mr. Jenner. 



Frond about as large as that of Staurastrum hh'sutum, deeply constricted 

 at the middle ; segments twice as broad as long, somewhat reniform, and fur- 

 nished with scattered spines. End view triangular ; the spines variable in 

 number and confined to the angles. 



Staurastrum teliferum differs from ^S. hirsutvm. in its longer spines, which 

 are also fewer, stouter, and in the end view confined to the angles. It is a 

 larger plant than »S'. Hystrix ; its spines are more numerous, and the end mar- 

 gins in the front view are convex. 



Length of frond ^^ of an inch ; breadth -^\^ ; breadth at constriction g-oVr? 

 length of spine -j-^ ; diameter of sporangium y|^ ; length of spine of sjjo- 

 rangium -^^. 



Tab. XXII. fig. 4. a. front \iew ; b. end view. 



Tab. XXXIV. fig. 14. Sporangium. 



13. S. Hystrix ; segments subquadrate, spinous ; end view with 



three or four rounded angles, each furnished with a few subulate 

 spines. 



Dolgelley, /. R. Near Storrington, Sussex, Mr. Jenner. 



Frond very minute, smaller than that of any other species with simple spines, 

 deeply constricted at the middle ; segments spinons, somewhat quadrilateral, 

 about twice as broad as long, the end margin nearly straight. The spines are 

 subulate, few in number, and in the front view most of them are lateral. The 

 end view is triangular or quadrangular, and has concave sides and rounded 

 angles. Six or eight spines are scattered on each angle, the sides and disk 

 being naked. 



Its smaller size and differently shaped segments will distinguish this species 

 from Staurastrum teliferum. 



Length of frond from -^-^^ to -^^ of an inch ; breadth from -^^ to -^ ; 

 breadth at constriction -^-^ ; length of spine -^^^^. 



Tab. XXII. fig. 5. a. front view of frond with endochrome ; h. front view 

 of empty frond ; c. end view ; d. transverse view of four-rayed variety. 



**** End view of frond showing four or more toothed lobes, which are 

 cither truncate or rounded, hut never elongated into rays. 



14. -S". quadrangulare (Breb.) ; frond smooth; segments quadrangular, 

 with a few marginal spines or teeth ; end view quadrilateral, with 

 truncate angles either emarginate or dentate. 



Staurastrum quadrangulare, Brcbisson, in lit. cum icone (184G). 

 Ambleside, Mr. Sidebothain. 

 Falaise, Brcljisson. 



