20 BRITISH DIATOMACE^. 



slightly produced ; V. scarcely siliceous ; striae 64 in "OOl". Length 

 •0008" to -0016". v.v. 



Brackish water. Iford, Sussex, Sept. 1852, W. Sm. 

 Supp. Plate XXX. 251. 



5. Amphora? tenera, TV. Sm. F. V. oblong, extremities round or 

 truncate ; V. scarcely siliceous, longitudinally rugose ; striae 62 in 

 •001". Length -0015" to -0025". v.v. 



Amphora lineolata, Kiitz. Bacill. v. 36. ad specim. authen. quae communicavit 

 cl. De Brebisson. 



Marine. Forms a thin pellicle on stones, &c. Seaford, May 1850. Lancing, 

 Nov. 1852, W. Sm. 



Supp. Plate XXX. fig. 252. 



6. Amphora membranacea, n. sp. F. V. elliptical, with rounded 

 extremities ; V. scarcely siliceous, with a central transverse band ; 

 striffi very faint, 80 in -001". Length -0013" to -0030". v.v. 



Brackish water. Poole Bay, Sept. 1848. Sussex, Sept. 1850, JF. Sm. 

 Near Belfast, Dr. Dickie. Near Harwich, Mr. Brightwell. 



Plate IT. 29. 



7. Amphora? costata,n.sp. V. longitudinally costate, costae marked 

 with a double line of moniliform puncta ; extremities produced. 

 Length -0020" to -0027". v.s. 



Marine. Poole Bay, Sept. 1851, W. Sm. 

 Supp. Plate XXX. 253. 



8. Amphora minutissima, n.sp. F. V. elliptical or oval ; V. marked 

 with a transverse band ; striae 64 in "OOl". v.v. 



Fresh water. Parasitic on Nitzschia sigmoidea. Near Lewes, Dec. 1850 and 

 Oct. 1852, W. Sm. In ponds near London, parasitic on Nitzschia linearis, 

 Mr. Shadbolt, Mar. 1851. 



Plate II. 30. 



