COSMARIUM. 115 



slightly constricted, sinus a wide and shallow depres- 

 sion; semicells broadly oblong-elliptic (subrotnnd), 

 apex broadly rounded. Vertical view circular. Cell- 

 wall smooth. Chloroplasts parietal, several in each 

 semicell, in the form of rather narrow and irregular 



o 



longitudinal bands, each with several small pyrenoids. 



Zygospore unknown. 



Length 90 //, ; breadth 45 p ; breadth of isthmus 37 {JL. 



IRELAND. Small lakes between Clifden and Round- 

 stone, and near Ballynahinch, Gralway ! 



This species is distinguished both by its outward form and 

 its peculiar chloroplasts. It was obtained in two localities in 

 the west of Ireland in 1890, but we have not seen it since. 



124. Cosmarium turgidum Breb. 

 (PL LXXV, figs. 1-3.) 



Cosmarium turgidum Breb. in Ealfs' Brit. Desni. 1848, p. 110, t. 32, f. 8 ; 



Arch, in Pritch. Infus. 1861, p. 735 ; Lnncl. Desni. Suec. 1871, p. 51 ; 



Nordst. Freshw. Alg. N. Zeal. 1888, p. 63 ; G-utw. Flor. Glon. Okolic 



Lwowa, 1891, p. 38 ; West, Alg. Engl. Lake Distr. 1892, p. 729 ; Lutkem. 



Desm. Millstattersees, 1900, p. 12. 

 Pleurotcenium turgidum De Bary, Conj. 1858, p. 75, t. 5, f. 31 ; Bulnli. in 



Hedwigia, 1859, p. 21, t. 2, f . 9 ; Kabenh. Flor. Europ. Alg. Ill, 1868, 



p. 144, c. fig. xylogr. p. 104 ; Hauptfl. Zellmenibr. 11. Hiillgallerte Desm. 



1888, p. 83, t. 2, f. 42, 47. 

 Dysphinctium turgidum Gruii. in Verli. d. zool. hot. Ges. Wien, 1858, 



pp. 493, 500; Keinscli, Algenfl. Frank. 1867, p, 179; Delp. Desm. 



subalp. 1877, p. 133, t. 21, f . 16 ; Heirnerl, Desm. alp. 1891, p. 594. 

 Docidium turgidum Wittr. Skandinav. Desm. 1869, p. 20. 

 Calocylindrus turgidus (Breb.) Kirclin. Alg. Schles. 1878, p. 142; Cooke, 



Brit. Desm. 1887, p. 127, t. 44, f. 1. 



Cosmarium Debaryi c. turgidum Klebs, Desm. Ostpreuss. 1879, p. 28. 

 Cosmaridium turgidum Hansg. Prodr. Algenfl. Bohm. 1888, p. 245. 

 Pleurotseniopsis turgidus (Breb.) De Toni, Syll. Alg.^1889,, p. 907; Mobius, 



Austral. Susswasseralg. 1892, p. 442 ; Lutkem. in Osterr. botan. Zeitschr. 



xliii, 1893, p. 43, t. 3, f. 26. 



Cells very large, 2-2^- times as long as broad, 

 slightly constricted, sinus a rounded notch ; semicells 

 ovate-truncate from a broad base, lower angles slightly 

 rounded, sides slightly convex and converging upwards, 

 apex truncately rounded. Vertical view circular. Cell- 

 wall minutely scrobiculate. Chloroplasts parietal, in 

 the form of somewhat irregular longitudinal bands, 8 

 in each semicell, with several pyrenoids* in each. 



Zygospore unknown. 



