Naviculacea.'] infusoeial animalcules. 355 



Epithemia llbrile = Eunotia lihrik (Ehr.) 



E. gibba = Eunotia gibba (Ehr.) — Large, straight, on secondary 

 sido, dorsum gibbous at its middle ; apices rounded, very obtuse ; 

 transverse strife parallel and very close ; on primary side, inflated at 

 both ends. Length 1-1 44th. 



E. ventricosa. — Straight ; on secondary side, dorsum gibbous at its 

 centre ; apices very obtuse, rounded ; transverse sti'ia3 parallel, close, 

 thirteen to fourteen in 1-1 200th ; on primary side ventricose at the 

 middle. Length 1 -450th. Germany. 



E. gramdata = Eunotia granulata (Ehr.) — Large ; on secondary 

 side slightly arcuate, dorsum convex, apices roimded, very obtuse, 

 recurved, ti'ansverse strite moniliform, six in 1-1 200th, their inter- 

 stices very finely punctate; on primary side, elongated, straight, 

 linear. Length 1-1 44th. 



E. Faba = Eunotia Faba (Ehr.) — Large, on secondary side slightly 

 arcuate, dorsum convex ; apices but very little recurved, obtuse ; 

 striae moniliform, seven to eight in I- 1200th, their interstices very 

 delicately punctate; primary side oblong, dilated at the middle 

 Length 1-1 80th. Fossil. 



E. vertagus. — Large, on secondary side slightly arcuate ; dorsum 

 convex, with rounded and reflexm apices ; striae transverse conver- 

 gent, ten in 1-1 200th, their interstices punctate; on primary side 

 oblong, rather dilated at the centre. Length 1-1 68th. Normandy. 



E. (?) cingulata = Eunotia cingulata (Ehr.) 



Genus ErrjrEEiDiON (Kiitz.) Cuneiform, prismatic, trapezoid, con- 

 joined in a wand or convoluted band, at length stalked. Striae trans- 

 verse, strong, unbroken. 



Kiitzing has created this genus in the belief that Meridion con- 

 strictum (Ealfs) possesses characters not belonging to Meridon, and 

 such as are sufficient to sepai'ate it. 



The bands developed, resemble, generally, in their convolution, 

 those of Meridion, but Kiitzing states that the transverse section of 

 the frustules is trapezoid, and that they are attached, like species of 

 Sgnedra, by a short, thick, gelatinous pedicle. 



E. constrictum = Meridon constrictmn (E,alfs.) 



Genus Ettnotia. — Lorica prismatic, striated, composed of one, two, 

 or more ineces or valves. Lower or ventral surface flat, or rather 



