BRITISH DIATOMACEiE. 7-^ 



16. Synedra aifinis, Kiitz. V. lanceolate, acute; striae marginal, 32 

 in -001"; frustules united in flabellate or radiating bundles. Length 

 •0021" to -0046". v.v. 



Kiitz. Bacill. xv. 6, ct 11. ad specim. authen, quae dedit amic. De Brebisson. 

 Marine. Pevensey Bay, Sussex, Apr. 1851. 

 Plate XII. 97. 



1 7. Synedra Arcus, Kutz. V. lanceolate, acute ; striae marginal, 

 30 in -001"; frustules on F. V. arcuate, flabellate. Length -0028" 

 to -0038". v.v. 



Kiitz. Bacill. xxx. 50 ? 



Marine. Cuckmere, Sussex, Mar. 1851 ; Jersey, Aug. 1852; Hastings, 

 Oct. 1852, W. Sm. 



Plate XL 98. Plate XII. m. 



18. Synedra hamata, n. sp. V. linear, or linear-lanceolate, suddenly 

 attenuated constricted and bent towards the extremities ; striae 

 marginal, 30 in -001". Length -0024" to -0052". v.v. 



Fresh water. Plumpton, Sussex, Apr. 1852, W. Sm. 

 Supp. Plate XXX. 264. 



19. Synedra Vaucheriae, Kiitz. V. 1 inear- lanceolate ; striae mar- 

 ginal, 30 in -OOl"; frustules somewhat flabellate. Length '0011" to 

 •0018". v.v. 



Kiitz. Bacill. xiv. 4 ? 



Fresh water : frequently attached to Vaucheria dichotoma and V. ccespitosa. 

 Lewes, Oct. 1851. 



Plate XI. 99. 



20. Synedra fasciculata, Kiitz. V. linear-lanceolate ; stride reach- 

 ing across the valve, 40 in -001"; frustules in rectangular tablets. 

 v.v. 



Kiitz. Bacill. xv. 5 ? Eocilaria fasciculata, Hass. Alg. xcvii. 3. ad specim. 

 authen. qua^, communicavit cl. Jenner. 



Fresh water. Plumpton, Sussex, Apr. 1852, W. Sm. 



Plate XI. 100. 



