238 Ernst Østrup. 



Lo с. Hvalrosodde, Vester Elv. 



Not before recorded from Arctic regions. Several other records. 



Cymbella naviculiformis Auersw., Cl. Syn., I, 166; Lgst., Spb., 



Tab. II, fig. 18 (Cymb. anglica). 



Lo c. Hvalrosodde. 



A ret. Distr. W. Greenl., E. Greenl., Spb., B. El. 



Cymbella septentrionalis sp. nova. Tab. nost. XIV, fig. 4. 



Long. 32—56^. Lal. 7 — 8//. Str. 14 in 10 |U, delicatissime trans- 

 verse lineatis. 



Valva fere cymbiformi, apicibus marginem dorsalem versus 

 paululum recurvatis. Margine ventrali subundulata. Raphe leniter 

 arcuata, area hyalina distincta, media in valva in aream centralem 

 longinam dilatata, cincta. Nodulis terminalibus marginem dorsalem 

 versus recurvatis. 



Lo c. Hvalrosodde (2 sampl.). 



Very nearly linear specimens of this species sometimes occur. 



Cymbella sinuata Greg., CI. Syn., I, 170; V. H. Trt., Tab. XXV, 



fig. 699 (^Cymb. abnormis). 



Loc. Hvalrosodde. 



Not before recorded from Arctic regions. Several other records. 



Cymbella stauroneiformis Lgst., CI. Syn., I, 165; Lgst., Spb., 

 Tab. I, fig. 15. 



Loc. Hvalrosodde (2 sampl.), Vester Elv. 

 Ar с t. Distr. E. Greenl., Fz. Js. Ld., Spb. 



Cymbella ventricosa Kütz., Cl. Syn., I, 168; V. H. Syn., Tab. III, 



fig. 15 (second fig. Encyon. ventr.). 



Loc. Vester Elv. 



Ar с t. Distr. \V. Greenl., E. Greenl., Fz. Js. Ld., Spb. 



Cymbella ventricosa var. ovata Grun., V. H. Trt., Tab. I, fig. 48 



(Encyon. cæspit. lata). 



Loc. Vester Elv. 



Not before recorded from Arctic regions. Several other records. 



Cymbella ventricosa var. semicircularis Lgst., Lgst., Spb., 

 Tab. II, fig. 20 (Cymb. affinis semicirc). 



Loc. Dove Bugt. 



Ar ct. Distr. E. Greenl., Spb. 



This variety, which Cleve (Syn. I, 168) places under Cymb. ventricosa 

 seems to be so peculiar in appearance that it certainly may be considered 

 a distinct variety. 



In a sample labelled "Nostoc" I found a Cymbella, which is figured in 

 V. H., Syn., Tab. Ill, fig. 18 as a "Forme moyenne entre ГЕпсуопета cœspito- 

 siim et ГЕпсуопета Lunula." 



