BRITISH DIATOMACEiE. 47 



3. Navicula Crassinervia, Breb. V. elliptical-lanceolate; extre- 

 mities produced ; striae obscure. Length '001 3" to '0026". v.s. 



"Navicula Crassinervia,'''' ad specimina sub hoc nomine quae misit cl. De 

 Bre'bisson, Sept. 1852. 



Fresh water. Wareham, Sept. 1849, W. Sm. Snow Mud, Grampians, 

 Vr. Dickie. Dolgelly, Mr. Ralfs. 



Supp. Plate XXXI. 271. 



4. Navicula serians^ Kliiz. V. acute ; transverse striae faint, 60 in 

 •001"; longitudinal distinct, 36 in 'OOl" ; frustules frequently co- 

 hering. Length -0017" to -0035". v. v. 



Kiitz. Bacill. xxviii. 43, xxx. 23, ad specimina quae communicavit cl. De 

 Brebisson in lit. Sept. 1852. 



Freshwater: boggy pools. Wareham, Sept. 1849, 77^^. (Sm. Forest Row, 

 Sussex, 3Ir. Jenner, Jan. 1844. Ben M'' Dhui, at an elevation of 3000 feet, 

 Mr. P. Grant. Lough Island-Reavey Deposit. (Lapland.) 



Plate XVI. 130. 



5. Navicula cuspidata, Kutz. V. acute ; striae parallel, distinct, 

 36 in -001". Length -0027" to -0062". v.v. 



Kiitz. Bacill. iii. 24 & 37. ad specim. authen. quae misit amic. De Brebisson. 

 Navicula fulv a, Ehr. Inf. xiii. 6. 



Fresh water: ditches. Lewes, Sept. 1850, W. Sm. Guildford, Mr. Capron. 

 Belfast, Dr. Dickie. Cantyre Peat. Lough Mourne and Peterhead Deposits. 



Plate XVI. 131. 



6. Navicula rhynchocephala, K'lltz. V. acute ; extremities pro- 

 duced, linear; striae distinct, radiate, 24 in *00l". v.s. 



Kiitz. Bacill. xxx. 35 ? 



Fresh water. Belfast, Dr. Dickie. 

 Plate XVI. 132. 



