304 Proceedings of the Royal Irish Academy. 
Breaches, near Newcastle. On moist rock, Black Castle, Co. Wick- 
low. Tacumshane, Co. Wexford. 
Var. acicularis, (Wm. Sm.) Fresh water. 
Resembling Synedra pulchella, only longer and narrower. (PI. 
2S, 1. UO) 
Wm. Sm., B.D., Vol.i., p. 20, Pl. x~ fie. 86, who reeards atas 
a brackish water form.—Synedra levis, Kiitz. Bac., p. 65, T. xyv., 
fig. 8. 2. 3.4. Were this the case, the variety should be attributed 
to Kiitzing, and be called var. levis; but Kiitzing’s figure is not 
sufficiently distinct to enable me to identify the variety with it, and 
therefore I deem it better to retain the name given by Smith, who 
figures it with accuracy.—Synedra Smithu, Ralfs, im Pritch., p. 786. 
Grunow, Verhand. der Zool. Bot. Gesel., Band xu., 1862, p. 892, who 
remarks, ‘‘that it 1s probably only a very long variety of (what he 
calls) Synedra fasciculata, mixed up with which he found it upon 
Cladophora flavida, Kiitz., on the Peene at Woolgart, and in such 
manner that no clear distinction existed between the two.” Jab. Fl. 
Kurs sect. lp. Tok. 
River Slaney, Killurin, Co. Wexford. Lough Gill, Co. Kerry. 
Carrickhugh, Co. Derry. Kilcool, moist rock, Black Castle, Co. 
Wicklow. In the last named locality, in which this form was found 
abundantly, marie influence was scarcely possible. 
Var. lanceolata, (Wm. Sm.) Fresh water. 
Resembling the typical form, but shorter and broader in proportion. 
(Pl. 28, fig. 20.) 
Synedra minutissma, Wm. Sm.,’B. 1).,- Vol..1.,, p. 70, Play 
fig. 87, who ascribes the species to Kiitzing, but the form so called by 
the last named author, Bac., p. 63, T. i., fig. 30, can scarcely be 
identical with it. More likely it is the same as that which Kiitzing 
describes as Synedra lanceolata: but whether or not this be the case, 
the designation is adopted because of its appropriateness, and the 
species attributed to Wm. Smith, whose figure admits of no mistake. 
Ralfs, in Pritch., p. 786. Heiberg, De Danske Diat., p. 65, who. 
attributes the form to fresh or brackish water. Rab. Fl. Eur., sect. 
1, p. 1389.—Synedra vaucherie, Grunow, who adopts this view with 
doubtfulness, Verhand. der K. K. Zool. Bot. Gesel., Band xu., 1862, 
p-393, T.v., fig.9. This last named author regards Synedra vaucherie,, 
Kiutz., as distinct from the form so named by Wm. Sm., and the 
former identical with that figured as Synedra minutissima, by Wm. 
Smith. 
River Slaney, Killurin, Co. Wexford. River at Port-na-Crush, 
and stream, Fintragh, Co. Donegal. Stream, Howth, Co. Dublin. 
Stream near Giants’ Causeway, Co. Antrim. Kilcool, Black Castle, 
Co. Wicklow. 
