BRITISH DIATOMACE^:. 31 



De Breb. Alg. Falaise, 1835, p. 53. pi. vii. ad spec, autlien. quse communi- 

 cavit cl. auctor. Hass. Alg. cii. 1. W. Sm. Ann. 2nd Ser. vol. vii. 

 pi. ii. 1. Prit. Anim. xviii. 20-26. Jen. Flo. Tun. p. 204. Nav. hi- 

 frons, Ehr. Inf. xiv. 2. Surirella bifrons, KUtz. Bacill. vii. 10. 



Fresh water. Boggy pools frequent, elsewhere occasionally. Wareham, 

 Dec. 1849 ; Lewes, Sept. 1851, ?r. Sm. Ashdown Forest, Sussex, Mr. Jenner. 

 Lough Mourne and Lough Island-Reavey Deposits, and Premnay Peat. 



Plate VIIL !r>7. Frustule with endochrome. Frontispiece, fig. LVII. 



2. Surirella linearis, n. sp. V. linear, occasionally constricted, 

 obtuse or acuminate, v.v. 



With the last, and probably varieties of it and S. splendida. Curwen Hill 

 Lot near Lancaster, Mr. Geo. Smith, 1851. Snow Mud, Ben M'^ Dhui, 

 Br. Dickie. Cantyre Peat, &c. 



Plate VIII. 58. 



3. Surirella constricta, W. Sm. F. V. linear, oblong ; V. elliptical, 

 acute, usually with a central constriction ; aire conspicuous ; cana- 

 liculi delicate, 10 to 12 in '001", reaching to central line, which is 

 often inflated. Length -0028" to -0055". v.v. 



W. Sm. Ann. 2nd Ser. vol. vii. p. 9. 



Brackish water. Near Lewes, Dec. 1850. Poole Bay, Sept. 1851. Lancing, 

 Sussex, Nov. 1852, TF. Sm. 



Plate VIII. 59. 



4. Sxirirella turgida, n. sp. V. much inflated, irregular in outline, 

 occasionally somewhat constricted towards the obtuse extremities ; 

 canaliculi few, conspicuous, 4 in '001". Length '0033" to 0052". 

 v.s. 



Fresh water. Lough Neagh, Dr. Dickie, 1850. 

 Plate IX. 60. 



5. Surirella lata, n. sp. V. elliptical, with rounded ends and 

 frequently with a central constriction ; canaliculi conspicuous, 3 or 

 4 in -001"; margin striated; striae 36 in -001". Length -0041" to 

 •0062". v.s. 



Marine. Coast of Skye, Prof. Williamson. Ilfracombe, Mr. Ralfs. 

 Plate IX. 61. 



