164 MR. W. WEST OS THE FRESHWATER 



incisura mediana latissima et brevi ; semicellulae subrotundatae, 

 apicibus late rotundatis; a vertice visae circulares; membrana 



lsevis. Massa chlorophyllacea in laminis parietalibus dispositis 

 irregulariter. 



Long. 90 /x ; lat. 45 /x. 



I. Lakes, Clifden to Roundstone ; Ballynahinch. 



106. Cosmarium De-Baryi, Arch. [Pleurotaenium cosma- 



rioides, Be Bart/ (Rabh. Fl. Europ. Alg. iii. p. 144). — Calo- 



cylindrus De-Baryi, Cooke, Brit. Besm. p. 128, tab. 44. fig. 4.] 



I. Near Westport ; Ballynahinch ; Derryclare Lough. 

 II. Lough Gruitaue ; near Lough Brin. 



107. C. ovale, Haifa Brit. Besm. p. 98, tab. 15. fig. 9. 

 Long. 182-188 ju; lat. 100-107 p ; lat. isthm. 30-35 p ; crass 



75 /li. 



I. Ballynahinch. — II. Adrigole. 



108. C. elegantissimum, Lund. {Besm. Suec. p. 53, tab. 3 

 fig. 20.) 



ttForma minor. (PI. XXIV. fig. 10.) 



Long. 50 /x ; lat. 23 /x ; lat. isthra. 19 /x. 

 II. Carrantuohill. 



1. Xanthidium armatuat, Breb. in Balfs, Brit. Besm. p. 112, 

 tab. 18. 



I. Ballynahinch ; Kyleinore ; Oorid Lough ; Arderry Lough ; 

 Lough Aunierin; near Oughterard ; Lakes near Recess ; Lakes, 

 Clifden to Eouudstone.— II. Glen Caragh ; Adrigole; Glen- 

 garriff; Castletown; Carrantuohill. 



ft Var. irregularis, nov. var. (PL XXII. fig. 1.) 

 Semicellulae suboctangulares sinu aperto (nee lineari); pro- 



cessibus subirregularibus irregulariter dispositis, aliis ad spinas 



simplices curvatas reductis. 



Long, sine proc. 160-165 fx ; lat. sine proc. 95-107 ; lat. cum 



proc. 110-123 fi; lat. apic. 55-59 /z; lat. isthm. 41-50 /x. 



1. Ballynahinch ; Kylemore. 



2. X. aculeatum:, JEhrenb. (Balfs, Brit. Besm. p. 113, tab. 19. 

 fig. 1.) 



IL Lough Guitane. 



