O'Meara — He-port on the Irish Diatomacece. 345 



towards the ends ; intermediate free space narrow, except in the cen- 

 tre, where it is somewhat rhombically expanded. (PL 30, fig. 11.) 

 Ralfs, in Pritch., p. 906. Donkin, IsT. H. Brit. Diat., p. 55, PI, 

 Tui., fig. 3. — Pinnularia longa, Gregory, Q,. J. M. S., Yol. iv., 1856, 

 p. 47, PL 5, fig. 18. Eab. PL Eui\ Alg., sect, i., p. 218. 



Arran Islands ; Stomachs of Ascidians, Eonndstone Bay, Co. 

 Galway. 



Navicula diver gens, (Wm. Sm.) Fresh water. 



Yalve oblong; length from about "0035 to -0055, breadth, from 

 about -0007 to -0012. Gibbous in the middle, attenuated towards the 

 slightly constricted and rounded extremities. Costse strong, con- 

 vergent in the middle, and radiate towards the ends. Intermediate 

 free space narrowed towards the ends, where there is a slight expan- 

 sion ; greatly expanded in the middle, reaching the margin in a tole- 

 rably broad stauroform band. 



Kalfs, in Pritch., p. 896. Grunow, Yerhand. der K. K. Zool. Bot. 

 OeseL, Band x., 1860, p. 523. Cleve, Om Svenska och J^orska 

 Diat., p. 225. — Pinnularia divergens, AYm. Sm., B. D., Yol. i., p. 57; 

 PL xviii., fig. 177. Eab. Fl. Eur. Alg. sect. L, p. 221. 



Drumoughty Lough, near Kenmare, County Kerry. Featherbed 

 ^Mountain, Killakee, County Dublin. Bantry, County Cork. Lake 

 near Castlewellan, County Down. Lough Moume deposit. County 

 Antrim. 



Navicida divergens, var. longa, (O'Meara.) Fresh water. 



Yalve oblong, linear. Length about '0059 ; breadth about "0008; 

 very slightly expanded in the middle and at the rounded ends. Costse 

 as in the typical form ; intermediate free space as in typical form, but 

 scarcely reaching the margin, compared with which it is relatively 

 narrower in middle, and broader at the ends. (PL 30, fig. 13.) 



Pond near the^City of Armagh. 



Navicula divergens, var. elliptica, (O'Meara.) Fresh water. 

 Like the typical species but broadly elliptical. 



Lough Mourne deposit, Co. Antrim. 



Kavicula horealis, (Ehr.) Fresh water. 



Yalve narrow, elliptical, with rounded ends. Length about "0015 ; 

 breadth about -0004. Costte short, parallel ; intermediate free space 

 relatively wide, elliptical. (PL 30, fig. 14.) 



Kiitz. Bac. p. 96. T. xxviii., figs. 68 72, (where it is identified with 

 Pinnularia borcalis, Ehr.) Grunow, Yerhand. der K. K. Zool. Bot. 

 GcseL, Band x., 1860, p. 518. — Pinnularia borcalis, Eab. Siissw. 



