18 P. T. CLEVE, DIATOMS FROM BAFFINS BAY AND. DAVIS STRAIT. 
Lower valve with distinct median line and nodules. WStriee, 
10 in 0,01 mm., costate, nearly parallel throughout. Ne 
areas. — P1. I, 5. 
> This is a remarkable species of the subgenus Micronic 
being, as ÖEsSTRUP has pointed out, most nearly related to 
A. Hauckiana. 3 
Actinocyclus alienus var. aretiea GRUN.. The form I have 
identified with this variety agrees perfectly with specimens 
in the Wankarema material, determined by GRUNOW, but 
differs in some respects from the figure in the VAN HEURCE's 
synopsis, as to structure, for which reason I have Sve a 
sketch of it. — PI. II, 11, 12. 
Amphiprora (7?) eoncilians CL. N. Sp. V. elongated, with 
obliquely attenuated, acute ends. =&L. 0,08; B. 0,009 mm: 
Median line sigmoid. No areas, and no junction-line. ' Strigae 
oblique, 25 in 0,01 mm. — Pl. I, 12, 13. 
Of this strange form a single valve only has been ob- 
served, for which reason the zone could not be examined. It 
is questionable whether this form really be an Amphiprora 
or a Navicula of the section Microstigmatice. 
A. (coffeiformis var.?) perpusilla GRUN. A few specimens, 
perfectly agreeing with GRUNow's figure and description were 
found. 
Chetoceros septentrionalis ÖESTR. In Arct. Diat. Pl. VIT 
f. 135 GRUNOW has figured a very strange form, which I believe 
may represent this species in a somewhat oblique position: 
At least, I have seen in my slides some specimens of C. sep- 
tentrionalis in such a position that they had some resemblance 
to GRUNOW's figure. 
Diploneis litoralis var. aretiea CL. N. var. L. 0,023 to 0,042; 
B. 0,014 to 0,021 mm. Strige 17 to 20 in 0,01 mm. not di- 
stinetly punctate. — PI. I, 7. 
This form is, as I know by examination of original spe- 
cimens, the same form which OzEstrRUP has figured Pl V f. 32 
as Nav. parca. 
Diploneis litoralis var. clathrata ÖESTR. (Nav. clat. ÖESTR. 
P1. III f. 15) is, as I have found by inspection of original 
specimens, a form with fine striation, intermediate between 
D. advena -and D. litoralis. — Pl. I, -2. 
Diploneis litoralis var. hyperborea CL. Linear with rounded 
ends. &L. 0,09; B. 0,018 mm. Furrows and central nodule 
