KONGL. SV. VET. AKADEMIKNS HANDUNGAK. BAND. 18. N:() 5. 7 



3. Navicula Grcenlandica Cl. N. Sp. 



Lanceolate with obtuse apices. Striae coarse, costate, very radiant and divergent, 

 crowded around the centre of the valve (T'^ i 0,01 mm.) more distant between the 

 centre and the ends ((> in 0,01 mm.), interrupted by furrows, parallel to the margins. 

 Around the central nodule there is a very large orbicular area. 



Length 0,117 ram. Breadth 0,023 mm. 

 PI. I, tig. 13, '""V.. 



Greenland, Davis Strait (very rare in Cl. et Moll. Diat. N:o 172). 



In its characters this species approches N. Trevelyana, but its form is entirely 

 different. The striaj are also more distant, being in N. Trevelyana 10 in 0,01 mm. 

 The terminal nodules of N. Gvcenlandia are peculiar and resemble those of N. Rec/vla 

 Cl. et Grdn. (Cl. W. Ind. Diat. p. 5, PI. 1, fig. 3.) 



4. Navicula Etigeniw Cl. N. Sp. 



Valve very convex, linear, with rounded ends. Stria' coarse, costate, radiant, 9 

 in 0,01 mm., reaching the median line, interrupted by a line parallel to the margin. 

 Median line undulate. Central nodule surrounded by a small area. Terminal -nodules 

 elongated. F. V. Frustule constricted in the middle; ends truncate. 



Length 0,0850,1 mm. Breadth 0,017 mm. 

 PI. II, fig. 16, '""7., a. S. v., h. F. V. 



Gallapagos Islands (Eugenie Exp.). 



5. Navicula Hennedyi var. undidata Cl. 



Oval with cunate ends and three undulations on each side. Stria? distinctly punc- 

 tate, marginal and around the median line. The striae near the uiedian line are 16 in 

 0,01 mm. as are also the marginal stria;, except in the constrictions between the un- 

 didations, where they are only 12 in 0,01 mm. 



Length 0,07 mm. Breadth 0,035 mm. 

 PI. II, fig. 19, '""Vi- 



Gallapagos Islands (Eugenie Exp.). 



This variety has finer strije thiin the other forms of the most variable N. Hen- 

 nedyi; the outline is also different. 



N. Hennedyi var. minuta Cl. 



Broadly oval, with the marginal punctate stria; (78 in U,01 mm.) separated 

 from each other by unusually large spaces. Central stria? 9 10 in 0,01 ram. 



Length 0,05 mm. Breadth 0,027 mm. 

 PI. I, fig. 15, '"7.. 



Gallapagos Islands (Eugenie Exp.). 



