40 BRITISH DIATOMACE^. 



Surirella multifasciata, Kutz. Bacill. iii. 47. et Synedra oxyrhynchus, Kiitz. 

 Sp. Alg. p. 44. ad specimina quae misit cl. De Brebisson, Sept. 1852. 



Fresh water : common. Lewes, March 1852, W. Sm. Wrav, Mr. G. Smith, 

 Nov. 1852. (Ceylon, Mr. Thioaites, Nov. 1850.) 



Plate XIII. 110. Supp. Plate XXXI. 110. 



8. Nitzschia tenuis, W. Sm. F. V. linear, occasionally slightly 

 sigmoid, extremities truncate ; V. narrow, lanceolate, acute ; striaa 

 obscure. Length -0042" to -0083". v.v. 



Synedra tergestina, Kiitz. Bacill. iv. 33. ad specimina quae communica\it cl. 

 De Brebisson, Oct. 1852. 



Fresh water. Near Lewes, March 1850, W. Sm. Wray near Lancaster, 

 Mr. G. Smith. 



Plate XIII. 111. 



Sect. III. Valves lanceolate. 



9. Nitzschia spathiilata, n. sp. F. V. linear-lanceolate, extremities 

 inflated ; V. lanceolate, acute, with a single row of puncta. Length 

 •0041" to -0083". v.s. 



" Nitzschia spatkulata," cl. De Brebisson inliteris cum speciminibus, Sept. 1852. 

 Marine. Hull, Mr. R. Harrison. 

 Supp. Plate XXXI. 268. 



10. Nitzschia angularis, n. sp. F. V. lanceolate, truncate ; V. lan- 

 ceolate ; keel central; puncta in a single row; surface of V. longi- 

 tudinally striated. Length -0041" to -0065". v.v. 



Marine. Coast of Sussex, July 1850, W. Sm. 

 Plate XIII. 117. 



11. Nitzschia lanceolata, W. Sm. F. V. lanceolate, extremities 

 acute ; V. linear lanceolate, acute ; keel eccentric ; surface of valve 

 marked by longitudinal lines, 21 in '001"; striae faint, 80 in "OOl". 

 Length -0048" to -0085". v.v. 



Surirella curvula, Breb. in Kiitz. Sp. Alg. p. 36. ad specimina quee commu- 

 nicavit cl. De Brebisson, Sept. 1852. 



Marine. Pevensey Bay, Sussex, Nov. 1850, TV. Sm. 



Plate XIV. 118. Ideal section of frustule undercoiiiff self-division, fig. 118. S. 



