O'Meara — Rejjort on the Irkh Biatomacece. 333 



«tate of tilings occurs, I have not found this \\c\7 confirmed. So that 

 probably Schizonema does not difPer in this respect from the rest of 

 the NaviculaB." — Untcrsuchungcn iiber Bau und Entwicklung der Bac- 

 illariaceen, p. 73. 



(f) Fnistules luith parallel strioe. 



Schizonema crucigerum, ("Wm. Sm.) Marine. 



' ' Frond filiform ; filaments implicate beloiv, free above, much 

 divided. Frustulcs crowded. Valves with a distinct stauros, lanceolate, 

 acute" ("Wm. Smith) on side view ; on front view wider in the middle 

 than at ends. Stride distinct, close, linear. (PI. 29, fig. 17.) 



In Smith's figure, the strite are described as slightly radiate, but 

 in my specimens, I find them parallel. 



Wm. Sm., B. D., Yol. ii., p. 74., PL M., fig. 354, and PI. Mi., 

 fig. 356. Ralfs, in Pritch., p. 928. Ptab. PI. Eur. sect. 1, p. 266. 

 — Stauroneis crucigera, Heiberg, De Danshe Diat., p. 88. 



Tacumshane, Co. "Wexford. Malahide, Portmarnock, Salt-hill, 

 Co. Dublin. Eostrevor, Co. Down. Lough Gill, Co. Kerry. 



Schizonema smithii, (Agardh.) Marine. 



' ' Frond, filiform, robust, simple below, much divided, fasciculated 

 and fastigiate above. Frustules in numerous closely set files. Valves 

 elliptico-lanceolate, acute." — Yfm. Smith. To which I would add, stria^, 

 obvious, extending to median line. Front view of frustule regularly 

 quadrangular. (PL 29, fig. 18.) 



Agardh. Conspectus, p. 18. Kiitz. Bac, p. 114, T. xxvii., fig. 5. 

 Wm. Sm., B. D., Vol. ii., p. 75, PL Ivii., fig. 362. Eab. Fl. Eur., 

 sect. 1, p. 269. — Micromega Sraithii, Ealfs, in Pritch., p. 930. 



Howth, Salt Hill, Malahide, Co. Dublin. Sea coast, Co. Antrim. 



Schizonema divergens, (Wm. Sm.) Marine. 



"Frond, simple below, sparingly divided, or by cohesion irregu- 

 larly submembranous above; ultimate ramuli short, obtuse." — Wm. 

 Smith. Valve, shorter and wider than the last, and more rounded at the 

 ends. Striae fijie, linear, reachiag the median line. 



Wm. Sm., B. D., Vol. ii., p. 7G, PL Ivii., fig. 363. Eab. Fl. Eur. 

 sect. 1, p. 269. — Micromega divergens, Ealfs, in Piitch., p. 931. 



Besides the locality named by Wm. Smith, Larue Lough, where it 

 was collected by Dr. Dickie, this species has been gathered by myself 

 at Malahide and Salt-hill, Co. Dublin ; and by Dr. David Moore, at 

 Carrickfergus and Carnlough Bay, Co. Antrim. 



Schizonema mucosum, (Kiitz.) Marine. 



"Frond filiform, gelatinous, simple below, by cohesion sub-mcm- 



2 Q2 



