Marine Diatoms 21F 
Navicula impressa Lager. 
Sch. Atlas, Pl. 46, figs. 31-34. 
Put by Cleve into N. cancellata Donk. where, like a lot of other forms so 
included, it does not belong. Found at Station 438c. 
Navicula inconspicua Greg. 
Cl. Nav. Diat., I, Pl. 5, fig. 28. 
Found at Station 23, scarce. 
Navicula incudiformis Cl., see N. transitans var. 
Navicula insignificans Mann, sp. nov. 
Pl. I, fig. 8. 
Valve narrow-lanceolate but with blunt ends; markings strikingly scanty, 
consisting of thin, widely spaced costal lines, obscurely cross-barred, on one side 
of the valve, and rows of beads, two beads long, on the other side of the valve, 
neither reaching to the rhaphe; this slightly tortuous, its outer ends strongly 
hooked; central nodule somewhat to one side of the middle. 
Length 0-064 mm., width 0-009 mm., 5-7 unbeaded costae and 6 beaded 
rows in 0-01 mm. 
This sufficiently resembles N. scalifer Brun, in Brun Espec. Nouv., p. 38, 
Pl. 15, fig. 4, to suggest its being a variety; but the similarity is not close. This 
is a smaller diatom (Brun’s having a length of 0-085 to 0-100 mm.) and that 
species is recorded only from the fossil deposit at Sendai, Japan. However, 
N. compressicauda occurs in both the North Sea and at Sendai, Japan. The 
above also resembles N. mendica Mann in Diat. Philippine Isl., Pl. 23, fig. 3. 
Found at Station 41. 
Navicula interrupta Kiitz. (not W. Sm.) 
Pl. I, fig. 9. Sch. Nordsee Diat., Pl. 1, fig. 8; Sch. Atlas, Pl. 69, fig. 25, 
misnamed. 
The form here figured and agreeing closely with the references given above 
may be a wide variety of Kiitzing’s species, at least as it is broadly represented. 
That no one would call it ‘‘interrupted”’ is evident, and in other points it does not 
resemble much Kiitzing’s type figure in Kiitz. Bacill., Pl. 29, fig. 93. Their 
identity cannot be decided without seeing Kiitzing’s type specimen, for many 
of his figures are greatly idealized. I accept the name, however, subject to the 
foregoing statement. Found at Stations 20b-c and 438c. 
Navicula Kepesii Grun. 
Grun. Diat. F. Jos. Land, Pl. 1, fig. 837; Cl. Nav. Diat., I, p. 27. 
It is hardly possible to hold this separate from N. directa W.Sm. Found at 
Stations 20b-c, 43b and 43c. 
Navicula lacrimans A. Sch. 
Sch. Atlas, Pl. 12, fig. 61. 
I doubt the advantage of Cleve’s renaming this N. gemmulata var. Grunowti 
Cl. Found only at Station 43d, scarce. 
Navicula lata Breb. 
Van Heurck Syn., Pl. 6, figs. 1-2. ; ; 
Probably merely a fresh-water interpolation; Station 23. 
Navicula Liber W. Sm. 
Sch. Atlas, Pl. 50, figs. 16-18. 
Although this fine species is variable, Cleve has nearly obliterated its 
meaning by uniting with it a host of slightly related forms in Cl. Nav. Diat., I, 
p. 54. Found at Station 20b-c. 
Navicula longa (Greg.) Ralfs. 
Sch. Atlas, Pl. 47, fig. 12, no name; and figs. 8, 9. ; . 
This variety is needlessly named N. capensis by Peragallo in Antare. Diat. 
France, p. 56. Found at Station 43a. 
3697—33 
