36 BRITISH DERMlPTACEvE. 



time, but separating previous to conjugation when 

 they become geniculate. Chloroplasts two or three, 

 forming parietal spiral bands, sometimes irregular. 

 Cell-wall densely and minutely granulate. 



Zygospores situated between the two conjugating 

 cells. 



1. Genicularia spirotaenia De Bary. 

 (PI. II, figs. 4-6 ; PI. V, figs. 3, 4.) 



Gonatozygon spirotsenia De Bary, in Hedwigia, 1856, p. 106. 



Genicularia spirotsenia De Bary, Conj. 1858, p. 77, t. iv, f. 1-22 ; Arch, 

 in Pritch. Infus. 1861, p. 721, t. iii, f . 3 (from De Bary) ; Rabenh. Flor. 

 Europ. Alo-ar. Ill, 1868, p. 156 ; Cooke, Brit. Desm. 1887, p. 184, t. 66, 

 f. 6; West & G. S. West, Notes Alg. Ill, 1903, p. S ( S c_-p.). 



Cells 10-20 times longer than their diameter, cylin- 

 drical ; apices very slightly dilated. Pyrenoids fairly 

 numerous in each chloroplast. Chloroplasts two or 

 three, making from 4-|-7-| turns. 



Zygospore globose and smooth. 



Length 200-400 n ; breadth 20-25 /u ; breadth of 

 apices 27-29 /m ; diam. zygosp. 48-57 p. 



ENGLAND. Hayle Pool, about four miles from the 

 Lizard, Cornwall ! 



Geogr. Distribution. Germany. Galicia in Austria. 



This rare Desmid has been observed twice from Cornwall, 

 hut is not known from any other part of the British Islands. 

 The genus Genicularia is one of the rarest of all known genera 

 of Desmids. 



2. Genicularia elegans West & G. S. West. 

 (Pl.V, figs. 1,2.) 



Genicularia elegans AVest & G. S. West, Scott. Freshw. Plankton, I, 1903, 

 p. 536, t. 14, f. 1, 2. 



* 



Cells 20-28 times longer than their diameter, cylin- 

 drical and slightly curved; apices slightly dilated. 

 Chloroplasts two, in very loose spirals making from 

 1-| 4 turns. Pyrenoids very numerous. 



Zygospore unknown. 



