EUASTRUM. 1 5 



Var. depauperatum rr. nov. (PI. XXXIV, fig. 10.) 



A variety with the interlobular incisions very shallow 



f / 



and widely open ; polar lobe more rounded and lateral 

 lobes very short. 



e/ 



Length 140 JJL ; breadth Go /u, ; breadth of isthmus 

 17ft. 



IRELAND. Xear Glenties, Donegal! 



' O 



"\Ve mentioned the occurrence of this form in the ' Alg. of 

 N. Ireland/ 1902, p. 27. 



Note. E. ol)longum var. integrum Benn. Alg. N. Cornwall, 

 1887, p. 16, t, 4, f. 18-; Cooke, Brit. Desm. 1887, t. 66, f. 1 

 (from Bennett) ; De Toiii, Syll. Algar. 1889, p. 1088. Bennett's 

 description of this form together with his bad figure make 

 future identification of it impossible. The " protuberances ' 

 he mentions are such as are not found in any Eiiastrum of 

 this group; neither is any form of E. oblongum known in 

 which the polar lobe is entire. (Consult remarks under 

 " E. crassum var. cornubiense" p. 8.) 



G. Euastrum Didelta (Turp.) Ralfs. 

 (PL XXXV. figs. 3-7.) 



? ? Heterocarpella Didelta Turp. Aper^ti organograph. 1828, p. 315, t. 13, 



f. 16. 

 ?? Cosmarium fenestratum Corda, Almanach de Carlsbad, 1839, p. 243, t. 5, 



f . 29. 

 Cosmarium Didelta ]\Ienegh. Syiiops. Desm. 1840, p. 219; Kiitz. Spec. Alg. 



1849, p. 174. 

 Euastrum Didelta (Turp.) Ealfs in Ann. Mag. Xat. Hist, xiv, 1844, p. 190, 



t. 7, f . 2 a and 6 only ; Hass. Brit. Freshw. Alg. 1845, p. 381, t. 90, f. 8 ; 



t. 91, f. 11 ; Ealfs, Brit. Desm. 1848, p. 84, t. 14, f. 1 ; Arch, in Pritch, 



Infus. 1861, p. 729, t. 1, f. 23-25 ; t. 3, f. 61 ; Rabenh. Flor. Europ. 



Algar. Ill, 1868, p. 184 ; Delp. Desm. subalp. 1873, p. 105, t. 6, f . 2 ; 



Kirchn. Alg. Schles. 1878, p. 157 ; Wolle, Desm. U.S. 1884, p. 99, t, 29. 



f . 9-10 ; Cooke, Brit. Desm. 1886, p. 69, t. 34, f . 1 ; Hansg. Prodr. 



Algenfl. Bohni. 1888, p. 205 ; De Toni, Syll. Alg. 1889, p. 1093 ; West, 



Alg. W. Ireland, 1892, p. 137 ; Alg. Eng" Lake Distr. 1892, p. 723 ; Roy 



& Biss. Scott. Desm. 1893, p. 176 ; Xordst. Index Desm. 1896, p. 106"; 



West & G. S. West, Alg. S. England, 1897, p. 483 ; G. S. West, Varia- 



tions Desm. 1899, p. 382, t. 8, f. 13-19 ; West & G. S. West, Alga-fl. 



Yorks. 1900, p. 61 ; Alg. N. Ireland, 1902, p. 28. 



E. Didelta var. sinuatvm Gay, Monogr. loc. Conj. 1884, p. 56, t. 1, f. 11. 

 E. Didelta a. typicum Racib. Xonn. Desm. Polon. 1885, p. 92. 

 E. Didelta b. tatricum Racib. I.e. t. 13, f. 3. 

 Helierellafenestrata Kuntze, Revis. gen. plant. 1891, p. 898. 



Cells moderately lars^e, twice or rather more than 



t/ O 



twice as long as broad, deeply constricted, sinus 





