O'Meara — Rejjort on the Irish Diatomacece. 357 



Nmicula macula, (Gregory). Marine. 



Valve broadly elliptical, with narrowed truncate ends ; length 

 •0014, breadth • 0008 ; costse fine, parallel; intermediate free space 

 narrow, except in the middle, where it expands greatly in quacli-angu- 

 lar form. (Plate 30, fig. 47.) 



Gregory, Q. J. M. S., 1856, p. 43, PI. v., fig. 9. Ealfs, in Pritch., 

 p. 896. Eab. PI. Eur. Alg., sect, i., p. 189. 



Lough Gill, Co. Kerry. 



Navicula zellensis, (Grunow). Presh water. 



Yalye narrow; length '0016, breadth '0003; ends produced; 

 margin triundulate ; striae very fine ; intermediate free space narrow, 

 except at the middle, where it expands in a short narrow stauroform 

 band. (Plate 30, fig. 48.) 



Grunow, Verhand. der K. K. Zool. Bot. Gesell., Band x., I860,, 

 p. 521, T. iii., fig. 34. Eab. PI. Eur. Alg., sect. 1, p. 207. 



Lough Derryvaragh, Co. "Westmeath. Camolin, Co. "Wexford. 



(c.) Ouspiclata. 



Valves more or less distinctly lanceolate ; ends sometimes produced ; 

 median line distinct ; intermediate free space narrow, hounded hj two 

 well-defined longitudinal ridges, one on either side of the median line. 



Navicula cuspidata, (Wm. Smith). Presh water. 



Valve large, lanceolate ; ends cuspidate ; length about '0070, 

 breadth '0015; striae close, fine, linear, parallel; median line with 

 slightly elongated expansions near the central nodule. (Plate 31, fig. 1.) 



Kiitz. Bac, p. 94, T. iii., figs. 24 and 27. "Wm. Sm. B. D., Vol. 

 i., p. 47, PI. xvi., fig. 131. Eab. Siissw. Diat., p. 37, T. vi., fig. 16. 

 This latter author remarks, that this form is very like Na^acula fulva, 

 but never attains the same size. This observation is not borne out by 

 the specimens I have had the opportunity of examining ; JSTavicula 

 cuspidata is usually the larger, sometimes very much so. Ealfs, in 

 Pritch., p. 905, PI. xii., fig. 5. Grunow, Verhand. der K. K. Zool. 

 Bot. Gesell., Band x., 1860, p. 528. The form referred to by Grunow 

 may possibly be different from the present, as he describes the striae 

 as somewhat radiate in the middle ; the striae in JS^. cuspidata being^ 

 parallel all through. Heiberg, De Danske Diat., p. 82. Cleve, Cm 

 Svenska och Norska Diat., p. 228. Donkin, N. H., Brit. Diat., p. 39, 

 PI. vi., fig. 6. 



Castlebridge, Tacumshane, Co. "Wexford. Derrylane Lough, 

 Stream, Crossdoney, Co. Cavan. Cushendun, Co. Antrim. Pond, 

 Botanic Gardens, Belfast, Co. Down. Bellarena, Co. Deny. Eiver 



■ 



