O'Meara — Be230rt on the Irish Diatomacece. 355 



Bot. Gesell., Band, x., 1860, p. 518, T. iy., fig. 15, which, represents the 

 costse as stronger and more distant than they are in my specimens. 

 — Stauroneis scalaris, Kiitz. Bac, p. 106, T. xxix., fig. 37. In this 

 figure the f oi-m is wider than in my specimens, and the stauroform band 

 is much narrower than in Grunow's figure, as well as in my specimens. 

 — -Stauroptera scalaris, Ehr., Eah. Siissw. Diat., p. 49, T. ix., fig. 8. 



Camolin, Co. "Wexford. 



Nmicula cxmeata, IS". S. Fresh water. 



Yalve linear, cuneate at the ends. Length .0025, breadth "0006. 

 Costse strong, convergent in the middle, radiate towards the ends ; 

 intermediate free space broad, expanded in the middle. (PI. 30, 



This form in outline much resembles Pinnularia acuminata, "Wm. 

 Sm., B. D., Yol. i., p. 55, PI. xviii., fig. 164, but differs from it 

 in the following details : — In the latter the striae are coarser, shorter, 

 and parallel, the intermediate free space is much wider than in this, 

 and haying no expansion such as is very obyious in the present form. 



Featherbed Bog, Co. Dublin. 



Nmicula acuminata, ("Wm. Sm.) Fresh water. 



Yalye linear, ends cuneate. Length -0029, breadth -0006. Costae 

 coarse, nearly parallel in the middle, and slightly radiate towards the 

 ends; intermediate free space wide. (PI. 30, fig. 41.) 



Balfs, in Pritch., p. 909. — Pinnularia acuminata, "\\''m. Sm., B. 

 D., Yol. i., p. 55, PL xyiii., fig. 164. llab. Fl. Eui\ Alg., sect, i., 

 p. 216. 



Featherbed Mountain, Killakee, Co. Dublin. Kilcool, Co. "Wick- 

 low. Eostrevor, Co. Down. 



Na/oicula return, (De Brebisson). Marine. 



Yalve narrow, oblong, rounded at the ends ; strise course, distant, 

 nearly parallel; intermediate free space relatively -^ade ; length -0026, 

 breadth -0004 ; frustule on front view constricted ; angles much 

 Tounded. (Plate 30, fig. 42.) 



De Breb., j^ote sur Diat. de littoral de Cherbourg., p. 16, fig. 6. 

 Ealfs, in Pritch., p. 908. Donkin, Q. J. M. S., 1857, p. 14, PI. i., fig. 

 17. Do. JN". H. Brit. Diat., p. 64, PI. x., fig. 3. Eab. Fl. Eur. Alg., 

 sect, i., p. 186. Donkin agrees with "Walker Arnott in regarding this 

 form as identical with Navicula pectinalis, "Wm. Sm., B. D., Yol. ii., 

 p. 91. 



Malahide, Co. Dublin. Arran Islands, Stomachs of Ascidians, 

 Eoundstone Bay, Co. Galway. 



