O'Meara — Eejiort on the Irish Diatomacece. 349 



■under the name of Navicula stauroptera, var. pai'va, Yerhand. der 

 K. K. Zool. Bot. GeseU., Band x., 1860, p. 517, T. ir., fig. 19. The 

 striation in the present form is, ho"^ever, coarser than in Grrunow's 

 figure, the latter also being more robust, for •which reasons I hesitate 

 to identify the present form with that of Grnnow. 



Lough I^eagh, near Lurgan, Co. Armagh. Camolin, Co. "Wex- 

 ford. 



Namcula liemiptera, (Kiitz). Fresh water. 



Valve linear, elliptical, -with rounded ends ; length '0025, breadth 

 '0005 ; stride costate linear, convergent at the middle, and radiate to- 

 wards the ends ; intermediate fi'ee space narrow, somewhat expanded 

 in the middle. (Plate 30, fig. 22.) 



Kiitz. Bac, p. 97, T. sxx., fig. 11. Ealfs, in Pritch., p. 908; 

 Gnmow, Yerhand. derK. K. Zool. Bot. Gesell., Bandx., 1860, p. 519. 

 This author considers the form may be only a variety of JSTavicula 

 viiidis, which it greatly resembles, except that it is smaller, and the 

 striation very much finer. Cleve, Om Svenska och jSTorska Diat., 

 p. 223. — Pinnularia hemiptera, "Wm. Sm., B.D., Yol. ii., p. 95. Eab. 

 Siissw. Diat., p. 42, T. vi., fig. 17. Do. PL Eur. Alg., sect. i. 

 p. 212. 



Lucan, Featherbed lEountain, Friarstown, Co. Dublin. Eivcr 

 Erne, near Crossdoney, Derrylane Lough, Co. Cavan. Lough Erne, 

 Co. Fermanagh. Lough ISTeagh, near Lurgan. TJlster Canal, near 

 Poyntzpass, Co. Ai'magh. Pool near Glengarriff, Co. Cork. Streamlet, 

 Cushendun, Co. Antrim. Eiver Bann, near Coleraine, Co. Derry. 

 Siib-peat deposit, Dromore, Co. Down. 



Navicida apiaiJata, (De Breb.) ilarine. 



Yalve linear in the roiddle, gi-adually tapering towards the ends, 

 which run out into acute short beaks ; length "0026, breadth '0008 ; 

 costce fine, converging in the middle, radiate towards the ends ; inter- 

 mediate free space narrower towards the ends, expanded in the middle. 

 (PL 30, fig. 23.) 



Pinnularia rostellata, Gregory, Diat. of Clyde, p. 488, PI. ix., fig. 

 20, 1857. — Xavicula apiculata, De Brebisson Diat. du Littoral de 

 Cherbourg, p. 16, PI. i., fig. 5, 1867. Ealfs, in Pritch., p. 903. Donkin 

 1^. H. Brit. Diat., p. 56, PL viii., fig. 6. Kiitzing has described 

 a form as ]S"avicula rostellata, "which is quite distinct from the present ; 

 it is therefore necessary to ch'op the specific name adopted by Gregory, 

 and substitute for it De Brebisson's name, jS'avicula apicrdata. 



Gregory and De Brebisson describe the strias as reaching the 

 median line ; Donkin more correctly represents them as falling short 

 of it, but does not describe the central expansion of the free inter- 

 mediate space. 



2112 



