BRITISH DESMIDIE.TC. 87 



(1844) ; Trons. ofBot. Soc. of Edinhnrgh, v. 2. p. 128. t. 1 1 . Ilass. Br. 

 Alg, p. 382. (not Cosmarium gemmatum, Urcb.). 

 Euastrum pectinatum, Br^b. in lit. cum. icone (1846). 



Boggy pools ; not rare. Dolgelley, Penzance, J. B. Sussex, and Weston 

 Bog near Southampton, 3Ir. Jenner. Brookhouse Moss, near Congleton, 

 Cheshire ; and Ambleside, Westmoreland, Mr. Sidehotham. Glen Derry, 

 Aberdeenshire, Dr. Dickie. Aberdeen and east of the Hill of Fare, Aberdeen- 

 shire ; and Moss Hagg, Banffshire, Mr. P. Grant. 



Falaise, France, M. De Brebisson. 



Frond two or three times longer than broad ; each segment has a broad 

 basal portion, which is somewhat quadrilateral, horizontal, and at each side 

 emarginate ; the neck is short and broad ; the terminal lobe is dilated ; the sides 

 entire in a. and slightly notched in ft ; the terminal notch is obsolete. 



A transverse view is twice as long as broad, with three lobes on each side 

 and two at each end. 



The end view shows that the terminal portion has two lobes at each end and 

 two lobules on each side, one belonging to each lobe. The empty frond is 

 punctate. 



Euastrum pectinatmn is a very distinct species, and differs from all the pre- 

 cedhig in the absence of a terminal notch, in the lobules of the end lobe, and 

 in having the ends emarginate in the transverse view. 



I formerly considered this species as the Cosmarium gemmatum of Mene- 

 ghmi's Synopsis. I am indebted to M. De Brebisson for the information that 

 it is distinct, and also for drawings of both plants. 



Sporangia gathered at Dolgelley are orbicular, with conical tubercles or short 

 obtuse spines. 



. Length of frond ^^ of an inch ; breadth at base -g\j ; breadth at end y^ ; 

 breadth of neck y^Vj ; breadth at constriction 2-bVj > diameter of sporangium 

 from -pio^ to -j\^. 



Tab. XIV. fig. 5. a. frond with endochrome ; b. empty frond; c. frond of 

 var. ft ; d. end view ; e. transverse view ; f. sporangium. 



13. E. gemmatum (Breb.); segments three-lobed; terminailobe dilated, 

 broadly emarginate ; basal lobes horizontal, emarginate, protube- 

 rances minutely granulate. 



Cosmarium gemmatum, Breb. Menegh. Synop. Desmid. in Linncea 1 840, p. 221 . 

 Eiiastrmn gemmation, Kutz. Phg. Gei'm. p. 134 (1845). Breb. in lit. cum 



icone. 

 Euastrum papulosum, Kiitz. Phy. Germ. p. 135 (1845). 



Bogs. Dolgelley and Penzance, J. B. Ambleside, Mr. Sidebotham. Aber- 

 deen, Dr. Dickie and Mr. P. Grant. Weston Bogs near Southampton, and 

 near Pulborough, Sussex, Mr. Jenner. 



Falaise, De Brebisson. Nordhausen, Prussia, Kilt zing. 



Frond about twice as long as broad ; segments three-lobed, the basal ones 

 horizontal, emarginate, and their projecting parts granulated. The end lobe 



