BRITISH DESMIDIE^. 127 



Gonioci/sfis {Trigonocystis) muricatu /3, Ilassall, Brit. Freshwater Alyce, 

 p. 351 (18-45). 



Sussex, Mr. Jenner. Dolgelley, J. R. 



Falaise, Brebisson. Germany, Ehrenherg, Corda, Kiitzing. 



Frond deeply constricted at the middle, nearly equal in length and breadth, 

 rough with minute conic granules or spines. End view triangular, its sides 

 convex and angles broadly rounded. 



Stoitrastrum mnricatum is larger than S. hirsutnm, and not hirsute, but 

 rough with stout short granules or spines ; in the end view also the sides are 

 more convex. 



Length of frond -j^-g of an inch ; breadth j^. 



Tab. XXII. fig. 2. a. front view ; b. end view. 



11. S. hirsiitum (Ehr.) ; segments semiorbicular, rough with nu- 

 merous hair-like spines ; end view with three rounded angles and 

 straight or slightly convex sides. 



Xanthidium hirstitum, Ehrenberg, Abh. der Bei'l. Ak. 1833, p. 318 ; Infus. 

 p. 147. t. 10. f. 22. Meneghini, Sijnop. Desmid. hiLinncea 1840, p. 224. 



Binatella hispid a, Brebisson, Alg. Fal. p. 58. t. 8 (1835). 



Xanthidium pilosum, Ehr. Bericht der Be?'l. Ak. 1836 (according to Mene- 

 ghini) . 



Stanrastnon mnricatum, Ralfs, Annals of Nat. Hist. v. 15. p. 154. t. 1 1 . f. 1 . 

 a, b, c (1845) ; Trans, of Bot. Soc. of Edinburgh, v. 2. p. 141. t. 14. 

 Jeimer, FL of Tnnbridge Wells, p. 194, 



Euastrum {Xanthidiuni) hirsutum, Kiitzing, Phycologia Gertnanica, p. 13/ 

 (1845). 



Goniocystis (Trigonocystis) miiricata, Hassall, Brit. Freshwater Alg ce, p. 351 

 (1845). 



Staiirastrum hirsutum, Brebisson, in lit. cum icone (1846). 



Dolgelley and Penzance, J. R. Sussex, 3Ir. Jenner. Ambleside, Mr. 

 Sidebotham. Rochdale, Mr. Coates. Yate, Mr. B?-oome. Aberdeenshire, 

 Mr. P. Grant. 



Germany, Ehrenberg, Kiitzing. Falaise, Brebisson, 



Frond variable in size, about equal in length and breadth, deeply constricted 

 at the middle ; segments semiorbicular, hirsute rather than spinous ; hairs 

 numerous, scattered. End view triangular ; the sides straight or slightly con- 

 vex, and the angles broadly rounded. 



I have gathered sporangia at Dolgelley and Penzance. They are orbicular, 

 their spines short, and branched at the apex. 



The hair-like spines are characteristic of this species. 



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

 breadth at constriction -gaVo 5 diameter of sporangium from yi^ to -^-^ ; length 

 of spine of sporangium ^ q\ ^ . 



Tab. XXII. fig. 3. a. front view of frond with endochrome ; b. front Aaew 

 of empty frond ; c. end view of frond with endochrome ; d. end view of empty 

 frond ; e. transverse view ; f immature sporangium ; g, h. mature sporangia. 



