103 



Navicula forcipata, Grev. 



Navicnla forcipata, Ralfs. in Prit. Infus. p. 897; Van Heurck, p. 94, pi. X, 

 fig. 6; O'Meara, p. 392; Donkin N. H. Brit. Diat. p. 12, pi. II, fig. 4- 



Valve elliptical with rounded extremities ;. striae linear punc- 

 tate, reaching to the median line ; slightly convergent at the 

 ends, and Intercepted by two longitudinal, free, lyrate spaces 

 which converge at the apices. 



//fl^._Marine. South beach. (Plate XC. fig. 4-) 



Navicula marina, Ralfs. 



Navicula marina, Ralfs in Prit. Inf. p. 903; Donkin, N. H. Br. Diat. p. 19 

 pi. III. fig. 5; Van Heurck, Syn. p. gS, pi. XI. fig. 16. 



Navicula piinctiilata, Sm. Syn. Vol. I. p. 52, pi. XVI. fig. 151; O'Meara Rep. 

 on the Irish Diat. p. 377, pi. 32, fig. i. 



Valve broadly elliptical with very slightly produced conic 



apices; striae distinctly moniliform. 



Hah. — Brackish water. South beach salt meadows at Garret- 

 sons. Rare. (Plate XC. fig. 8.) 



Although this species is described as marine in the " Synop- 

 sis" of Prof. Smith, I have never found it in purely marine local- 



ngener N. granidata is found 



Navicula permagna, Bail. 



Donkin. 



Navicula permagna. Bail. Smiths. Contr. 1850, p. 4, pl- H- ^g- 28; Vanileurck, 

 Syn. p. 102, pl. XI. fig. I; Ralfs in Prit. Inf. p. 907. 



Valve broadly lanceolate with obtuse apices, stout terminal 

 nodules and broad median, longitudinal free space ; stria; costate, 

 radiant, interrupted near the margin of the valve by a depression. 



/T*?^. —Brackish. Salt meadows at Garretsons. Scarce. (Plate 

 XC. fig. 9.) 



Stauroneis Phcenicenteron, Ehr. 



Stauroneis Fhccnicenteron, Kutz. Bacill. p. 104, t. III. fig. 53 ; Sm. Syn. p* 

 59, pi. XIX. fig. 185; Van Heurck, p. 67. pl. IV. fig. 2; Brun. Diat. of the Alps 

 and Jura, p. 88, pl. IX. fig. 7; Rab. Siissw. Diat. p. 47, t. IX. fig. i; Ralfs. in 

 Prit. Inf. p. 913. 



Bacillaria Phcenicenteron, Nitsch, 18 17. ' 



Cymbella Phcenicenteron, Ag., Conspec. p. 10. 



Navicnla Pha'nicenteron, Ehr. 



Valve lanceolate with more or less produced obtuse extremi- 

 ties ; stauronelform, free space reaching to the margins; striae 



uies 



pand between the centre and the ends. 



