298 Proceedings of the Royal Irish Academy. 



Grunow describes tlie stipes as short, and occasionally slightly 

 branched. Kiitzing regards this species as identical with. Diatoma 

 crystalliniim of Agardh, and suggests, with a note of doubtfulness, that 

 it may be the same as Echinella fasciculata of Lyngbye. Smith con- 

 firms the former opinion, and that on the inspection of authentic spe- 

 cimens. Heiberg, who seems to have had the opportunity of inspecting 

 authentic specimens of Lyngbye's species, considers it the same as the 

 present. The species I attribute to Lyngbye, and adopt Agardh's 

 name to obviate confusion with other species named S. fasciculata. 



Kiitz. Bac, p. 69, T. xvi., fig. 1. "Wm. Sm., B.D., Yol. i., p. 74, 

 PI. xii., fig. 101. Ealfs, in. Pritch., p. 789. Grunow, Verhand der 

 K. K. Zool. Pot. Gesel., Band xii., 1862, p. 407. Heiberg, De Danske 

 Diat., p. 64. Pab. PI. Eur., sect. 1, p. 139. — Diatoma chrystalli- 

 num, Agardh Consp., p. 52. — Echinella fasciculata, Lyngb. Tent. 

 Hydi'ophyt. Dan., p. 210. 



On sea-weeds, Salthill, Co. Dublin, Prom stomachs of Ascidians, 

 Poundstone Bay, Co. Galway. On sea-weeds, near Dundalk, Co. 

 Louth. On sea-weeds, Belfast Lough, Co. Antrim. 



Syned/ra fulgens, (Greville.) Marine. 



Similar to the preceding species, with which it is often associated,, 

 but may be distinguished by the greater delicacy of the strise. The 

 stipes as described by Kiitzing is long and branched. (PL 28, fig. 7.) 



Wm. Sm., B. D., Yol. i., p. 74, PI. xii., fig. 103. Ealfs, in 

 Pritch., p. 789. Grunow, Yerhand der K. K. Zool. Bot. Gesel., Band 

 xii., 1862, p. 408. Kaben. PL Eur., sect. 1, p. 140. -Cleye, Om 

 Svenska och Norska Diat., p. 220. — Lichmophora fulgens, Kiitz. 

 Bac, p. 123, T. xiii., fig. 5. Kiitzing and Smith concur in the iden- 

 tification of this species with Exilaria fulgens, Greville, who has a 

 prior claim to the authorship of this species. 



Salt ditch near Wexford. Bannow, Co. "Wexford. Sea-weeds, 

 Malahide. Stomachs of Pectens, Dublin Bay. Dollymount, Co. Dublin. 

 Stomachs of Ascidians, Co. Clare. Sea-weeds, Dundalk, Co. Louth. 

 Sea-weeds, Belfast Lough, Co. Antrim. 



Synedra laculus, (Greg.) Marine. 



Similar to preceding species, but not expanded at the middle or 

 ends as it is ; strise somewhat coarser, and without the submarginal 

 longitudinal lines. (PL 28, fig. 8.) 



Gregory, Q. J. M. S. Trans., Yol. v., 1857, p. 88, PL i., fig. 54. 



Sea-weeds, Co. Clare, Stomachs of Ascidians, Eoundstone Bay„ 

 Co. Galway. 



