80 BRITISH DESMIDIE/E. 



The side view, which is not so broad as the front one, is inflated at the base, 

 attenuated upwards into a short neck, and emarginate and shghtly dilated at 

 the end. A transverse view is oblong, with three inflations at each side and 

 a smaller one at each end. The terminal lobe, as seen by an end ^dew, is 

 four-lobed. 



Euastrum verrucosiim, when once seen, is not liable to be confounded with 

 any other species, but may be known by the conic granules giving a dentate 

 appearance to the outline. 



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



Tab. XI. fig. 2. a. frond with endochrome ; b. empty frond ; c. side view ; 

 d. end view. 



2. E. oblongum (Grev.) ; frond smooth, oblong ; segments five-lobed ; 

 lobes cuneate, emarginate, the terminal one partly included between 

 the lateral ones. 



Echinella ohlonga, Grev. in Hook. Br. Fl. v. 2. p. 398 (1830). 



Euastrum Pecten, Ehr. Abh. d. Berl. Ak. 1831, p. 82 ; Infus. p. 162. t. 12. 

 f. 4. Kiitz. Phy. Germ. p. 135. 



Cosmarium sinuosum, Corda, Ahn. de Carlsb. 1835, p. 121. t. 2. f. 21. 



Micrasterias sinuata, Breb. Alg. Fal. p. 55. t. 7. (1835). 



Cosmarium oblongum, Breb. in Menegh. Synop. Desmid. in Linncea 1840, 

 p. 221. 



Eutomia oblonga, Harv. Br. Alg. p. 188 (1841). 



Euastrum oblongum, Ralfs, in Annals of Nat. Hist. v. 14. p. 189. t. 6. f. 4. 

 (1844) ; Trans. Bot. Soc. Edin. v. 2. p. 126. t. 10. Hass. Brit. Fresh- 

 water Alg. p. 380. 



Hab. Pools ; common. Appin, Capt. Carmichael. Penzance ; Dolgelley 

 and Carnarvon, J. R. Warbleton, Henfield, &c., Sussex ; Tunbridge Wells ; 

 Reigate, Surrey ; and Weston Bog near Southampton, Mr. Jenner. Brook- 

 house Moss, near Congleton, Cheshire, and near Ambleside, Westmoreland, 

 Mr. Sidebotham. Aberdeen, Mr. P. Grant and Dr. Dickie. 



Falaise, Brebisson. Germany, Ehrenberg, Kiitzing. New York ; Rhode 

 Island and Virginia, Bailey. 



Frond comparatively large, appearing to the naked eye Uke a small dot, 

 oblong, three or four times longer than broad ; each segment divided into five 

 lobes in a pinnatifid manner. The lateral lobes are broad, cuneate, vdth a 

 broad shallow notch. The terminal lobe is cuneate and its notch linear ; the 

 corners of all the lobes are rounded. The empty fronds are punctated. 



The transverse view is three times longer than broad, and has three rather 

 distant inflations or lobes on each side (the largest in the centre) and one at 

 each end. I have not seen the end view myself, but Mr. Jenner finds the 

 terminal lobe twice as long as broad, slightly constricted at the middle, its 

 ends notched rather than lobed. 



The sporangia are orbicular, and furnished with numerous conical tubercles ; 

 they have been met with only near Dolgelley. 



The young fronds are smaller and have the middle lobe entire. 



Length of frond -—-^ of an inch ; breadth -^^ ; breadth of end lobe -g-Lg- ; 

 diameter of sporangium ^yy ; length of tubercle -j-wo • 



