16 BRITISH DIATOMACE.Ii. 



the concave margin; striae delicate, 36 in "001 ". Length •0012" 

 to -0029". v.v. 



Navicula Arcus, Ehr. Inf. xxi. 10. Cymbellal Arcus, Hass. Alg. c. 6. Ce- 

 ratoneis Arcus, Kiltz. Bacill. vi. 10. 



Fresh water. In boggy pools, Dorsetshire, Jan. 1849, W. Sm. Wray 

 near Lancaster, Jan. 1852, Mr. Geo. Smith. Mountains in Forfarshire, Dr. 

 Dickie. 



Plate II. 1.5. Frustules with endochrome, Frontispiece, v. i. fig. XV. 



2. Eunotia gracilis, n. sp. V. arcuate, extremities recurved ; striae 

 delicate, 42 in -001". Length -0006" to -0018". v.v. 



Fresh water. Wareham, Sept. 1849, W. Sm. Jack's Wood Spring, Tun- 

 bridge Wells, 3Ir. E. Jenner. 



Supp. Plate XXX. 249. 



3. Eunotia monodon, Ehr'. V. regularly arcuate, obtuse, extre- 

 mities slightly produced ; striae 34 in '001". v.s. 



Ralfs, Ann. vol. xiii. pi. xiv. 1 . 



Fresh water. Ben M'= Dhui, at an elevation of 3000 feet, Mr. P. Grant. 

 Aberdeenshire, Dr. Dickie. 



Plate II. 16. 



4. Eunotia diodon, EJir. V. with two dorsal ridges; striae 32 in 

 •001". v.s. 



Ehr. Inf. xxi. 23. Ralfs, Ann. vol. xiii. pi. xiv. 2. Hass. Alg. xcA-ii. 6. 

 Kiitz. Bacill. v. 24. 



Fresh water. Aberdeenshire, Dr. Dickie. Ben M" Dhui, Mr. P. Grant. 



Plate II. 17. 



5. Eunotia triodon, Ehr. V. with three dorsal ridges ; stride 

 40 in -001". Length -0015" to •0026". v.s. 



Ehr. Inf. xxi. 24. Prit. Anim. iii. 164. Hass. Alg. xcvii. 7. Kiitz. Bacill. 

 V. 25. 



Freshwater. Ben M'^ Dhui, at an elevation of 3000 feet, Mr. P. Grant. 

 (Lapland.) 



Plate II. 18. 



6. Eunotia tetraodon, Ehr. V. with four dorsal ridges; striae 

 24 in •OOl". Length -0015" to -0022". v.v. 



Ehr. Inf. xxi. 25. Ralfs, Ann. vol. xiii. pi. xiv. 4. Hass. Alg. xcvii. 8. 

 Kutz. Bacill. V. 26. 



