68 BRITISH DIATOMACE^. 



W. Sm. Ann. 2nd Ser, vol. ix. p. 10. pi. ii. 8. Prit. Anim. xx. 8. 



Marine. Coast of Sussex, Nov. 1850, W. Sm. Southampton, Mr. /mwer. 

 River Orwell, near Ipswich, Mr. Hodgson. (Coast of Normandy, M. De 

 Brebisso7i.) 



Plate XXII. 214. 



23. Pleurosigma Hippocampus, W. Sm. V. broadly lanceolate, 

 obtuse, flexure considerable ; colour pale brown ; long, striae 32 in 

 •001"; trans, stricfi 40 in -001". Length -0050" to '0066". v.v. 



W. Sm. Ann. 2nd Ser. vol. ix. p. 10. pi. ii. 9, 10. Prit. Anim. xx. 9, 10. 

 Navicula Hippocampus, Ehr. Inf. xiii. 1 1 1 Kiitz. Bacill. iv. 29 ? Prit. 

 Anim. iii. 145. 



Brackish water. "Brooks" near Lewes, Sept. 1850, W. Sm. Hull, 

 Mr.R. Harrison. Titchwell, Norfolk, Mr. BrightweU, Sept. 1851. 



Plate XXII. 215. Outline of young (?) specimen, 215/3. 



24. Pleurosigma attenuatum, W. Sm. V. lanceolate, obtuse, flex- 

 ure moderate; colour purplish brow^n; long. stricC 30 in '001 ", 

 trans, striee 40 in -001". Length -0075" to -0108". v.v. 



W. Sm. Ann. 2nd Ser. vol. ix. p. 11. pi. ii. 11, 12 & 13. Prit. Anim. xx. 

 11, 12 & 13. Navicula Hippocampus, Quekett on the Microscope, 

 pi. viii. figs. 1, 2,3. Dujar. Inf. xx. 1. Gyrosigtna Hi2ipocampa, Hass. 

 Alg. cii. 1 1 ? Navicula attenuata, Kiitz. Bacill. iv. 28. 



Fresh water : frequent in streams and ditches. River Froome, Dorsetshire, 

 May 1849; Plumpton, Sussex, and many other places, Apr. 1851, W. Sm. 

 Guildford, Mr. Capron. Lough Mourne Deposit. Peterhead Deposit. Can- 

 tyre Peat. 



Plate XXII. 216. Outline of F. V. in S. D. 216 </. Outline of young (?) 

 specimen, 216/3. 



25. Pleurosigma lacustre, W. Sm. V. lanceolate, acute, flexure 

 considerable ; colour pale brown ; long, and trans, striae 48 in -001". 

 Length -0052" to -0068". v.v. 



W. Sm. Ann. 2nd Ser. vol. ix. p. 12. pi. ii. 14. Prit. Anim. xx. 14. 

 Fresh water. Brooks and ponds near Lewes, Oct. 1851, W. Sm. 

 Plate XXI. 217. 



26. Pleurosigma Spencerii, W. Sm. V. lanceolate, obtuse, flexure 

 slight ; colour pale brown ; " trans, striae 50 in -001", long, striae 

 55 in -OOl"." (R. B.) Length -0033" to '0041". v.v. 



