430 DIATOMACE^. 



Navicula phoeniceiiteron Elir., Die Infus. p. 175. t. xiii. 

 fig. 1. 13. 



Hah. Cheshunt : A. H. H. — Yar. Q. Gardener Street : 

 Mr. Jenner. 



It is possible that the variety /5 of Ehrenberg, which is that 

 here described under the name of N. j^hcenicenteroiiy is really 

 distinct. The frustule is not transversely striated, but several 

 longitudinal lines may frequently be noticed running along 

 the centre of each. 



2. Navicula palea Hass. 



Plate CII. Fig. 10. 



Char. Frustules small, smooth. In front view attenuated, 

 with truncate extremities ; in side aspect lanceolate. 



Navicula gracilis Ehr., Die Infus. p. 176. t. xiii. fig. 2. 

 Frustulia gracilis Jenner, in Flora of Tunbridge Wells, 

 p. 204. Cgmhella avenacea Breb. et Godey. 



PiV^^Y Hab. Cheshunt: A. H. H. In the great bog near Forest 



Ji'bt/ Row ; bogs at Fisher's Castle, &c. : Mr. Jenner, 



This species resembles N. 'phce.nicenteron in miniature. 



3. Navicula amphisb^na Bory. 



Plate CII. Fig. 5. 



Char. Frustules elongated. In front view quadrangular, 

 loith straight sides ; in lateral aspect oval, prolonged at 

 each end into a blunt process. 



Navicula amphisbcena Bory, Encycl. Meth. 1824. Navi- 

 cula amphisbcena Turpin, Diction, des Sc. Nat. 1828. 

 N ventricosa, Abhandl. der Akademie d. Wissensch. zu 

 Berlin, 1830, p. 67. N. amphisboena, Abhandl. &c. 

 1833 (1832), p. 254. Frustulia cuspidata Kiitz., Lin- 

 naea, 1833, p. 549. t. xiv. fig. 26. N. amphisboina. Die 

 Infus. p. 178. t. xiii. f. 7. Cymhella appendiculata 

 Godey et Breb. 



r 



