304 EUNOTIA. 



var. subarcuata (Naeg.) Grun. (H.V.H. Atl., pi. 35, f. 2*), plate 

 9. fi g- 385- 



Valve short, rather broad, strongly arcuate. 



var. bilunaris (Ehr.) Grun. (H.V.H. Atl., pi. 35, f. 6B*), plate 

 9, fig. 386. 



Valve rather short, flexuous. 



E. flexuosa KutZ. (Spec. Alg. p. 6 ; H.V.H. Atl., pi. 35, f. 9 and 

 10*), plate 9, fig. 387. 



Valves straight, sometimes somewhat arcuate or somewhat flexuous, with 

 apices inflated, capitate, nodules well marked; striae delicate, 11 or 12 in 

 1 c.d.m., distinctly punctate ; girdle face linear, with connecting membrane 

 very delicately striate-punctate. Length, 15 to 30 c.d.m. 



Fresh water. Rare? 



var. bicapitata Grun. (Synedra biceps IV. Sm. ; H.V.H. Atl., pi. 

 35, f. 11*), plate 9, fig. 388. 



Valve broader, with apices more strongly inflated. 



Amphicampa Ehr. (1849). A genus created by Ehrenberg for 

 certain Eunotia, which presented no other differentiating characters than 

 having the two margins indented. 



At the expense of this genus he further created in 1869 two others. 

 Ehrenberg called Ophidoaimpa forms having equal and alternate indentations 

 on the dorsum and venter, and he called Heterocampa forms with a valve 

 inflated at the median portion. 



Climacidium Ehr. (1869), is another synonym of Eunotia. It com- 

 prehends forms quadrangular in girdle view, with valves having the dorsal 

 margin indented and truncate, and apices rounded. 



E monodon, triodon, tdraodon, etc., are also Climacidium, according to 

 Ehrenberg. 



Desmogonium Ehr. (1848). This genus comprises forms which, in 

 our opinion, cannot remain united. 



Desmogonium gracile Eul. (Eul. Spec, Type No. 150), from South 

 Africa, has frustules furnished with terminal nodules, inflated at the apices, 

 and united by its apices in long filaments by means of short filaments of 

 interposed coleoderm. This species ought to be arranged by the side of 

 Eunotia flexuosa. 



