O'Meara — Report on the Irish Diatoinacece. 301 



«oine"wliat radiately arranged. They differ as respects the character 

 -of the striation. In Synedra barbatiila the striae are easily detected, 

 and are divided by a narrow, longitudinal sulcus ; in the smaller spe- 

 cimens of Synedra gracilis the striation is obscure, but in the larger 

 forms the striae are apparent and peryious. 



From stomachs of Ascidians, Roundstone Bay, Co. Galway. Prom 

 seaweeds, Drehidnamaud, Co. Kerry. Seaweeds, Salthill, Co. Dub- 

 lin. Seaweeds, Tramore, Co. Waterford. Seaweeds, Greenore, Co. 

 Louth. 



(b.) Frustules arcuate on side view, dri<s pervious. 



Synedra undulata, (Bail.) Marine. 



Frustules veiy long and narrow, with undulate margias ; expanded 

 in the middle and towards the ends ; strise moniliform. (PI. 28, 

 fig. 14.) 



Gregory, Diat. of Clyde, p. 59, PI. xiv., fig. 107. ^"m. Sm., B.D., 

 Tol. ii., p. 97. RaKs, in Pritch., p. 786. Grunow, Yerhand. der K.K. 

 Zool. Bot. Gesel., Band xii., p. 405, T. vi., fig. 1. Cleve, Om Svenska 

 och Xorska Diat., p. 220. Eab. Fl. Eui-., sect. 1, p. 130.— Toxarium 

 undulatum, Bailey, Hie. Obs., p. 15, figs. 24, 25. 



Grunow associates this species with forms characterised by the 

 fact of the strise being interrupted in the middle, and it is so repre- 

 sented in the figui'e above referred to ; but I have ever found the 

 strios per"sious, as in Gregory's figui'e. 



Stomachs of Ascidians, Co. Clare. Stomachs of Ascidians, Eound- 

 stone Bay, Co. Galway. Stomachs of Ascidians, and also fi'om sea- 

 weeds, in great abundance, Belfast Lough, Co. Antrim. 



Synedra lunaris, (Ehr.) Fresh water. 



Frustules on front view quacbangular ; on side view arcuate, at- 

 tenuated towards the extremities; striae linear, fine, but distinct; stipes 

 short. (PL 28, fig. 15.) 



Ehi'. Infus., T. xviii., fig. 4. Kiitz. Bac, p. 65, T. iii., fig. 11. 

 Vm. Sm., B. D., Yol. i., p. 69, PI. xi., fig. 82. Ptab. Siissw. Diat., 

 p. 54, T. v., fig. 6. Ealfs, in Pritch., p. 185. Grunow, Yerhand. der 

 K. K. Zool. Bot. Gesel., Band xii., 1862, p. 389. Heiberg, De Danske 

 Diat., p. 65. Eab. Fl. Eur., sect. 1, p. 128. Cleve, Om Svenska och 

 ISTorska Diat., p. 220. Castracane, Catalogo di Diat. raccolte nell Yal 

 latrasca, p. 10. 



Lucan, Co. Dublin. Glenchree, Glenmalurc, Co. "Wicklow. 

 Dcrrylanc Lough, Co. Cavan. Bellarena, Co. Londonderiy. Five- 

 miletown, Lisnaskea, Co. Fermanagh. Pool, Glencar, Drumoughty 

 Lough, near Kenmare, Co. Kerry. Bantry, Co. Cork. . Connemara, 

 Co. Galway. 



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