AMPHORA. 



135 



A. inflexa (Breb.) H. L. Sm. (in Lens, 1873, p. 78.) 



Under the name of Amphipleura inflexa, De Brebisson has described a 

 rather singular diatom which he found on the coast of Normandy. 



In 1868, Eulenstein formed the genus Okedenia with this species, and in our 



" Types du synopsis " we distributed it under the name of Okedenia inflexa, Eul. 



After a careful study of this form, the result of which I communicated to 



Professor Cleve, the learned diatomographer thought that this diatom was 



simply an Amphora of the sub-genus Halamphora. Professor H. L. Smith 



had previously classed it among the Amphora ; I therefore 



place it here under the name of A. inflexa. No correct 



figure of this diatom having yet been published we give 



here. one of our photograms of it. 



Valves narrow, arcuate, with apices unilaterally capitate, 

 recurved. Sutural zone very narrow on dorsal side, more or 

 less developed on ventral side, and displaying a more or less 

 considerable number of pleats. Raphe inflexed, quite on 

 the margin of the frustule and scarcely visible. Central 

 nodule very elongate and more or less rudimentary. Valve 

 with puncta forming transverse striae (about 18 in 1 c.d.m.) 

 and longitudinal lines. Connecting zone finely striate trans- 

 Fig. 25.^. versely, about 20 striae in 1 c.d.m. Length, 10 to 12 c.d.m. 



(Okedenia) inflexa. Breadth of valv6j mther j ess than , c d m at the med ; an 



portion. Breadth of frustule, 7 to 15 //. 



Marine. North Sea : France (Breb !) ; England (W. Sm. !) 



A. Sarniensis Grev. (t.m.s. 1862, h\, n.s., p. 95, pi. 9, f. 12; 



Ad. Schm. Atl.,pl. 25, f. 80*), plate 24, fig. 682. 



Frustule constricted at the median portion, with bi-undulated lobes, apices 

 truncate, produced. Striae about 12 in 1 c.d.m. Length, 4 to 5-5 c.d.m. 



Marine Guernsey (Wallich). 



A. Ergadensis Greg. (Diat. of Clyde, p. 40, pi. 4, f. 71*), plate 



24, fig. 683. 



Frustule elliptic lanceolate, with apices diminuate. sub-rostrate-truncate. 

 Valves very narrow with raphe approximate to the ventral margin, which is 

 flat ; dorsal margin regularly arcuate, extremely obtuse, somewhat prolonged- 

 capitate. Transverse striae strong, with difficulty resolvable into puncta, 9 in 1 

 cd.m. Connecting zone showing 3 to 5 longitudinal rows of coarse puncta. 

 Length, 8 to 9 c.d.m. ; breadth at the median portion, about 1*5 c.d.m. 



Marine Lamlash Bay, Loch Fine (Scotland, Greg.) 



