O'Meara — Beport on tJie Irish Diatomacece. 363 



Navicxda ampliishmna, (Bory). Eresh -vx^atcr. 



Yalve broadly elliptical, with produeed capitate ends, longitudinal 

 . ■sulci close to the margin; intermediate free space lanceolate, broad 

 in the middle. Striae fine, linear, close, radiate ; length "0035, 

 breadth -2013. (PI. 31, fig. 18.) 



Kiitz. Bac, p. 95, T. iii., figs. 41 and 42. This author regards 

 the species as identical with jS^avicnla amphisbsena, Bory, 1824, to 

 whom, therefore, it should be attributed. 1\"m. Sm., B. D., Yol. i., p. 

 5], PI. xvii., fig. 147. Ealfs, inPritch., p. 899, PI. vii., fig. 72. Eab. 

 Sussw. Liat., p. 40, T. vi., fig. 66. Grunow, Yerhand. der K. K. 

 Zool. Bot. Gesell., Band x., 1860, p. 36. Heiberg, De Danske Diat., 

 p. 82. Cleye, Om Svenska och jSTorska Diat,, p. 227, Donkin, IS,. H. 

 Brit. Diat., p. 36, PI. y. fig. 13. 



Biver Dodder, Dundrum, Blackrock, Malahide, Co. Dublin. Biver 

 Bann, Coleraine, Bellarena, Co. Derry. Caumlough, near Tralee. 

 Lough Grill, Co. Keny. Breaches, near Newcastle, Co. Wicklow. 

 Tacumshane, Co. "Wexford, 



Nmicula suls<dina, (Ehr.) Brackish water. 



In all respects resembling J^Tavicula amphisbaena, except that the 

 ends are not capitate, nor so much produced. 



Donkin, X. H. Brit. Diat,, p. 24, PL iv., fig. 2.— IS^avicula am- 

 phisbaena, var. (i. Wm. Sm., B.D., Yol. i., p. 51; PL xttI., fig. 147 ^. 

 The last-named author attributes the species to Ehrenberg. Cleve, 

 Diatoms from Arctic Sea, p. 18. This form occurs frequently, mixed 

 with jSTavicula amphisbsena, in places accessible to marine influences, 

 but I have never found it in perfectly fresh water. So that, with 

 Donkin, I am disposed to consider it may be a distinct species. 



Tacumshane, Co. Wexford. Breaches, Co. Wicklow. Caumlough, 

 near Tralee. Lough Gill, Co. Kerry. Malahide, Co. Dublin. 



Navicula elegans, (Wm. Sm.) Marine or brackish water. 



Yalve elliptical, lanceolate ; longitudinal sulci marginal. Stride 

 distinct, linear, convergent in the middle, afterwards radiate ; inter- 

 mediate free space narrow, except in the middle, where it expands 

 considerably; length about -0038, breadth about -00065. (PL 31, 

 fig. 19.) 



Wm. Sm. B. D., Yol. i., p. 49. PL xvi. fig. 137. Ealfs, in Pritch., 

 p. 907. Heiberg, De Danske Diat., p. 85. Eab. El. Eur. Alg., sect, 

 i., p. 182. Donkin, IS". H. Brit., Diat., p. 23, PL iv., fig. 1. This 

 form is obviously distinct from that described under the name of If avi- 

 cula elegans by Grunow, Yerhand. der K. K. Zool. Bot. Gesell., Band 

 X., 1860, T.iv., fig. 37. 



Blackrock, Co. DubKn. Caumlough, near Tralee. Lough Gill, 

 Co. Kerry. Galway Bay. Breaches, Kilcool, Co. Wicklow. Tacum- 

 shane, Co. "Wexford. 



H I. A. PROC, SER. II., VOL. II., SCIENCE. 2 S 



