50 BRITISH DIATOMACE^. 



Navicula latiuscula, Kutz. Bacill. v. 40. specim. authen. misit cl. DeBrebisson. 

 Fresh water. Marl, Co, Down. 

 Plate XVI. 139. 



17. Navicula palpebralis, Breb. V. elliptical, acute; striae not 

 reaching central line, 27 in '001". Length -0015" to -0032". v.s. 



"Navicula palpebralis," cl. De Brebisson in lit. Sept. 1852. 

 Marine. Poole Bay, Aug. 1848. Hull, Mr. R. Harrison. 

 Supp. Plate XXXI. 273. 



Sect. IV. Valves inflated ; extremities rounded. 



18. Navicida obtusa, n. sp. V. elliptical, contracted towards the 

 rounded extremities ; striae distinct, 33 in '001", not reaching the 

 central line. v.s. 



Fresh water. Raasay Earth. Marl, Co. Down. Lough Moume Deposit. 

 Plate XVI. 140. 



19. Navicula Semen, ifw^^r. V. oval, contracted towards the rounded 

 extremities ; striae distinct, 26 in '001". v.s. 



Kiitz. Bacill. xxviii. 49. 

 Fresh water. Peterhead Deposit. Lough Moume Deposit, &c. 

 Plate XVI. 141. 



20. Navicula a£Bims, Ehr. V. elliptical, contracted, and linear to- 

 wards the rounded extremities, v.s. 



Ehr, in Kiitz. Bacill. xxx. 45 ? 



Fresh water. Guildford, Mr. Capron. 

 Plate XVI. 143. 



21. Navicula inflata, KUtz. V. elliptical, inflated; extremities ob- 

 tuse ; striae distinct, 28 in '001". v.s. 



Kiitz. Bacill. iii. 36. 



Fresh water. Guildford, Mr. Capron. Peterhead Deposit. 

 Plate XVII. 158. 



