KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND. I8. wn:o 5. 9 
9. Navicula Platessa Cu. N. Sp. 
Small, broadly elliptic, with mucronate apices. Stria strong, smooth, 8 in 0,01 
mm., marginal, leaving around the median line a very large area. 
Length 0,028 mm. Breadth 0,018 mm. 
PL, fe lee 
Gallapagos Islands rare (Eugenie Exp.). 
This little Navicula belong to the Palpebralis-group, but differs from all de- 
scribed forms of that section by its short, distant and coarse striae. 
10. Navicula Hauckit Cu. N. Sp. 
Very long and slender, linear, somewhat gibbous in the middle and near the 
ends, convex. Strie punctate, 15 in the middle of the valve, 16 towards the ends and 18 
in 0,01 mm. in the ends, a little shortened around the central nodule and not reaching 
the median line, which is surrounded by a linear area. The striw are interrupted by 
a very fine line parallel with the margin. 
Length 0,128 mm. Breadth 0,012 mm. 
ole: Th ne 0 Te ge 
Adriatic Sea, Rovigno, stomachs of Holothurians. leg. F. Hauck (rare in Ct. et 
Mott. Diat. N:o 208—210). 
This species seems to belong to the section Nav. limos@ and is allied to N. ma- 
azima, N. formosa etc. 
11. Navicula Febigerii Ci. N. Sp. 
Lanceolate, with produced, obtuse ends. Strie 16 in 0,01 mm., composed of 
distinct puncta, reaching the median line. In the middle they are alternately longer 
and shorter around the central nodule, which is surrounded by a broad area. 
Length 0,054 mm. Breadth 0,02 mm. 
PIS tgs Be. 
Oakland Bridge, California in a sample sent by Mr. Cur. Frpicer. 
This beautiful little species has some resemblance to Achnanthes Danica (FLocEt) 
Grun., but seems to be a true Navicula, belonging to the section »punctate». 
12. Navicula Cluthensis var.? maculifera Ot. 
Broadly oval, with rounded ends. Striw radiant, reaching the median line, ab- 
breviated around the central nodule, which is surrounded by a tolerably large area. 
Number of strie, (which are composed of distinct puncta), 11—12 in 0,01 mm. 
Length 0,05 mm. Breadth 0,026 mm. 
Pl. UU, fig. 23, "7. 
Slightly brackish water, near Waxholm, entrance to Stockholm (Mr. LacErstept). 
This. form has closer strie than the typical species and an area around the no- 
dule. Another smaller form is probably. 
K. Sv. Vet-Akad. Handl. Band. 18. Nio 5. 2 
