CLOSTKK'irM. 123 



1848, p. 170, t. 29, f. 2 a-g ; Arch, in Pritch. Infiis. 1861, p. 749, t. 2, 

 f. 2 and 6 ; Kabenh. Flor. Europ. Algar. Ill, 1S6S, p. 242 ; Kin-lm. Alg. 

 Schles. 1878, p. 139 (a. genuinum) ; 'Jay, Mon. loc. Conj. 1884, p. 71; -, 

 Wolle, Frcshw. Alg. U.S. INS", p. 24, t. 55, f. 5-8 ; Cook'e, Brit. Desm. 

 1SN6, p. 29, t. 11, f. 1; Hansg. I'rudr. Aigmfl. liohm. INSS, pp. |sn and 

 242; Hauptfl. Zellm. u. Hiillgallerte Desm. 1888, p. 99, t. :;. t. 2N : \\Vst . 

 Alg. W. Ireland, 1S92, p. 124; K..y .V liiss. Scott. Dcrfin. 1N9I-, p. 249: 

 Nordst. Index D.'.sm. 1N96, p. 242 I Wrsl \ G. S. West, Desm. Singa- 

 pore, 1897, p. 159; Alg. S. England, 1N97, p. 1M ; Some Desm. U.S. 

 INKS, p. 284; G. S. West, Variation Desm. 1N99, p. 3sn ; \\Vst ,V G. S. 

 West, Al-'a-fl. Ym-ks. 19UO, p. 55 ; Alg. N. Ireland, 1902, p. 24 ; Fn-slnv. 

 Al--. Ceylon, 1902, p. i:;7. 



( '/. striolatum var. tn,niil nm Kabenh. Flor. Europ. Algar. Ill, 1868, p. 12l> ; 

 De Toni, Syll. Algar. 1889, p. 826. 



Cl. striolattitn a. I i/i>i<'inn Jvleljs, Desm. Ostprenss. 1879, p. 14, t. 2, f. -In. 



Cl. striolatum var. <n-/h<iiii<l urn Eoy, Freshw. Alg. Enbriclge Lake and 

 Vicin. 1890, p. 336; West, Alg. W. Ireland, 1N92, p. 124 L'oy \ Uiss. 

 Scott. Desm. 1S9J, p. 21.9; West ,V G. S. West, Alg. S. England, 

 1897, p. 481 ; Alga-fi. Yorks. 1900, p. 55. 



Arthrudia striolata Knntze, Eevis. gen. plant. 1891, p. 884. 



Cells of medium size, 8-12 times longer than their 

 diameter, moderately curved, outer margin from 30 to 

 ()1) of arc, inner margin concave, never tumid, but 

 sometimes straight in the middle, gradually attenuated 

 to the apices, which are broad and truncate with 

 rounded angles ; cell-wall yellowish or yellowish-brown 

 in colour, striated, with 14-21 strias visible across the 

 cell ; each chloroplast with about 6 ridges and an 

 axile row of 5-7 pyrenoids ; terminal vacuoles with 

 many moving granules. 



Zygospore globose and smooth, often enveloped in a 

 copious mucus. 



Distance between apices (= length) 235-478 yu, ; 

 breadth 22-53 /a; breadth of apices 10-14 //, ; diam. of 

 zygosp. 65 /A. 



ENGLAND. Cumberland ! Westmoreland ! (Kulfx). 

 W., N., and E. Yorks ! Lancashire ! (Jfalf*). Cheshire 

 (7.V//V). Leicester (Jioi/). Warwick (Wills). Herts 

 (Hassall). Suffolk! Middlesex! Kent! (7.W/V). Surrey! 

 (llalfs). Sussex (Kalfa). Hants! (Rolfs). Devon! 

 Cornwall! (Ralfa). 



WALES. General and abundant (at 2,200 ft. on 

 Glyder Facli) ! 



SCOTLAND. General ! (Uoij $ tiiwtt). Common in 

 Outer Hebrides ! Orkneys ! Shetlands ! 



