O'Meara — Report on the Irish Diatomacecc. 247 



GreviUe, in Hooker's Brit. Flora,* p. 401. TVm. Sm. B.D., Yol. ii., 

 p. 56; PL L., fig. 330. Heiberg, De Danske Diat., p. 28.-31. moni- 

 liformis, Kiitz. Bac, p. 53, T. iii., fig. 2. Eaben. Fl. Eur., p. 38. 



Ealfs, in Pritcli., p. 817, PL r., fig. 71. 



Ptiver Slaney, near Killurin, Co. "Wexford. Brackish. ditcK near 

 "Wexford town. !Malaliide, Dollymount strand, Ho-wth, Co. Dublin. 

 Sea "sveeds. Giants' Causeway, Co. Antrim. Brackish, ditch, near the 

 town of "Wicklow. E. IS'annywater, Laytown, Co. 34eath, 



Melosira sulflexiJis, (Kiitz.) Preshi or bracki.sh water. 



Prustules usually narrow elongate, slightly infiexed upon the 

 margin. (PL 26, fig. 2.) 



Kutz. Bac, p. 53, T.ii., fig. 13. Wm. Sm., B.D., Yol. ii., p. 57, 

 PL LI., fig. 331. Heiberg, De Danske Diat., p. 28. Eab. PL Eiu\, 

 p. 39. 



Considerable diversity of opinion exists as to the habitat of this 

 species. According to Kiitzing it belongs to the fresh, water forms, 

 having been found by him in rapid brooks. "In schnell fliessenden 

 Bachen." Bac, p. 54. Still more precisely does Eabenhorst assign 

 to it a fresh water habitat. " Hab. in rivulis Sporadice per totam 

 Europam e planitie usque in regionem montanam superiorem, PL Eur., 

 p. 39. "While Smith gives it either a fiTsh water or brackish locality, 

 Heiberg makes it a marine species. His remarks are worthy of notice. 

 "Smith attributes the authorship of this species to Kiitzing, but 

 Kiitzing' s figure can hardly be identified with ceilainty, and seems to 

 be more properly refeiTible to ^Melosira varians. Kiitzing's Melosii'a 

 Jurgensii more nearly resembles Smith's species, and so Prit chard 

 accepts it. But Pritchard calls the species ITelosira Jurgensii, and 

 represents lEelosira subflexilis Sm. as a synonym; but in any case 

 this ought to be reversed, inasmuch as Smith was the first to defioie 

 the species so that it could be identified with certainty." "Smith 

 assigns it to fresh water, but as the localities mentioned are near the 

 mouths of rivers, the species possibly has been borne out along with the 

 floods." De Danske Diat., pp. 28, 29. In addition, I have only to say 

 that the localities in which the species has been found by me La 

 Ireland are marine, but still liable to the access of fresh water. 



Lough Foyle, Bellarena, Co. Deny. Grcystones, Co. "Wicklow. 



Melosira varians, (Agardh.) Eresh water. 



Ends of the frustules not so convex as in the preceding species. 



Kutz. Bac, p. 54, T. ii., fig. 10. Eab. Die Sussw Diat., p. 13, 



T. ii., fig. 4. Wm. Sm. B.D., Yol. ii., p. 57, PL li., fig. 332. Ealfs, 



* For explanation of contractions andlist of references, vide List at end of Eeport. 



