58 BRITISH DIATOMACE^. 



19. Pinnularia Johnsonii, n. sp. V. linear, with central and ter- 

 minal inflations; costae reaching central line, 56 in "OOl". Length 

 •0042" to -0072". v.v. 



/3. Inflations very slight. Length -0025" to -0035". v.v. 



Marine or brackish water. PiUing near Lancaster, Mr. Johnson, Feb. 1851. 

 /3. Shoreham, Sussex, Mar. 1851, W. Sm. 



Plate XIX. 179. Var. /3. PI. XIX. 179 13. 



20. Pinnularia gibba, Ehr. V. linear, with central and terminal 

 inflations ; costae not reaching central line, contiguous, 30 in '001". 

 v.v. 



Navicula acrosphcBria, Kiitz. Bacill. v. 2. Sp. Alg. p. 78. ad specim. quae 

 misit amic. De Brebisson. 



Fresh water. Boggy pools, Wareham, Sept. 1847, W. Sm. Curwen Hill, 

 Lancashire, Mr. G. Smith. Cantyre Peat. Premnay Peat. 



Plate XIX. 180. 



21. Pinnularia Tabellaria, W. Sm. V. as in the last, but central 

 inflation more distinct; costse subdistant, 22 in 'OOl". v.v. 



Navicula tabellaria, Kiitz. Bacill. xxviii. 79. Prit. Anim. xv. 21. 

 Fresh water. Lewes, Sept. 1850, W. Sm. 

 Plate XIX. 181. 



22. PinniUaria acrosphseria, W. Sm. V. as in the last two ; infla- 

 tions more distinct; costae distant, 16 in "OOl". v.v. 



Fresh water. Near Lewes, Sept. 1850, W. Sm. Premnay Peat. Dol- 

 gelly Earth. 



Plate XIX. 183. 



23. PinnTilaria mesolepta, Ehr. V. linear, with three central in- 

 flations, deeply constricted towards the obtuse extremities ; costas 

 reaching central line, 24 in "OOl". v.v. 



Navicula mesolepta, Kiitz. Bacill. xxviii. 73. xxx. 34 ? Navicula nodosa, 

 Ehr. Inf. xiii. 9. 



Fresh water. Ashdown Forest, Sept. 1850, W. Sm. Gardner Street, Sussex, 

 Mr. Jenner. Near Aberdeen, Dr. Vickie. Marl, Co. Down. Lough Mourne 

 Deposit. Dolgelly Earth. Premnay Peat. Cantyre Peat. 



Plate XIX. 182. 



