84 BRITISH DIATOMACE^. 



Genus 28. RHIPIDOPHORA, Kutz. 



Frustules stipitate, cuneate ; valves convex, obovate, inflected at larger 

 extremity, traversed by a median line. 



1. Rhipidophora paradoxa, Kutz. Stipes dichotomous ; frustules 

 on F. V. obovate, rounded at the upper extremity ; V. rounded at 

 upper, acute at lower extremity, occasionally faintly striated. 

 Length -0016" to -0025". v. v. 



Kiitz. Bacill. x. 5. Echinella paradoxa, Lyng. Tent. Ixx. fig. E. Gompho- 

 nema paradoxum, Ag. Consp. p. 34. ad specim. quae communicavit cl. 

 Dr. Greville. Ralfs, Ann. vol. xii. pi. xviii. 10. 



Marine: frequent. Jersey, Aug. 1852, W. Sm. Penzance, Mr. Ralfs. 

 Aberdeen, Dr. Dickie. Frith of Forth, Dr. Greville. 



Plate XXV. 231. 



2. Rhipidophora elongata, Kiitz. Stipes dichotomous ; F.V. nearly 

 linear, truncate ; V. somewhat acute ; striae obscure. Length '0032" 

 to -0042". v.s. 



Kiitz. Bacill. x. 6 ? Gomjjhonetna tinctum, Ag. Consp. p. 35. ad specimina 

 quae communicavit cl. Dr. Greville. 



Marine. Frith of Forth, Dr. Greville, 1849. Cromarty, Mr. Johnson. 



Plate XXV. 232. 



3. Rhipidophora Dalmatica, Kiitz. Stipes incrassated, irregularly 

 branched ; F.V. truncate ; V. very narrow, somewhat acute ; striae 

 obscure. Length -0008" to -0016". v.v. 



Kutz. Bacill. ix. 7 ? 



Marine. Hastings and Beachy Head, Sussex, July 1850, W. Sm. 

 Plate XXV. 230. 



