KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 93 



Var. oblongella N^egbli (1849). — V. linear elliptical. L. 0,o2 to 0,038; B. 0,oo65 to o,oi mm. 

 Rows of alveoli 13 to 19 in 0,5 1 mm. Puncta 20 to 25 in 0,oi mm. — Nav. oblongella 'Nmg. Kutz 

 Sp. Alg. p. 890. V. H. Syn. PI. X f. 12. Nav. ovalis var. fossilis Pant. II p. 51 PL VI f. 115 (1889)? 



Fresh water: Iceland! Finland! Paris! Konigsberg, fossil! 



54. D. notabilis G-rev. (1863). — V. elliptical. L. 0,025 to 0,o8; B. 0,02 to 0,035 mm. 

 Central nodule large, quadrate. Furrows Linear, arcuate, moderately broad. Transverse costis 7 

 to 10 in 0.01 mm. alternating witb large, elongated alveoli, forming 4 to 5 longitudinal, undulating 

 rows, more close towards tbe margins. 



Forma genuina — Rows of alveoli one to three along the margin and one along the furrow. 

 Nav. notab. Grbv. T. M. S. XI p. 18 f. 9. A. S. Atl. VIII f. 46, 47, 48. 



Forma expleta A. S. (1874). — Rows of alveoli filling the whole space between the furrow 

 and the margins. — N notabilis var. expleta A. S. N. S. D. I f. 20, II f. 11. Atl. VIII f. 49 to 52. 



Marine: North Sea! Mediterranean Sea! Black Sea! Red Sea! Ceylon! Madagascar! Cape of 

 Good Hope! Java! Labuan! Sandwich Islands! West Indies! Brazil! 



55. D. Graeffli Grun. (1875). — V. elongated elliptical. L. 0,o65 to 0,12; B. 0,025 to 0,o42 

 mm. Central nodule small, rounded quadrate. Furrows broad, gradually narrowed from the middle 

 and crossed by faint prolongations of the costse. Costse 7 to 8 in 0,oi mm., alternating with single 

 rows of quadrate alveoli, 8 to 11 in 0,oi mm. and forming 7 to 8 longitudinal rows on each side 

 of the furrows. — Nav. Grceffii A. S. Atl. VII f. 5, 6. 



Marine: Bab el mandeb! Seychelles! Madagascar! Manilla! Java! Sumbava! Labuan! Japan 

 (Atl.), Samoa (Atl.), Tahiti! 



Forma minor. — L. 0,o6; B. 0,oi8 mm. — A. S. Atl. VIII f. 33. 



Marine: Campeachy Bank (Atl.). 



This species seems to be intermediata between I), notabilis and D. fusca. 



56. D. fusca Greg. (1857). — V. elliptical or subrectangular, not constricted. L. 0,o7 to 

 0,14; B. 0,038 to 0,075 mm. Central nodule moderately large, quadrate. Furrows broad, gradually 

 tapering from the middle and crossed by faint prolongations of the costse, frequently alternating 

 with double rows of obliquely disposed puncta. CostiB 6 to 10 in 0,oi mm. alternating with rows 

 of more or less quadrate alveoli, forming more or less regular, longitudinal rows, equidistant with, 

 to twice as close as, the costse. 



Var. Pelagi A. S. (1875). — V. rhombic-elliptical. L. 0,055 to 0,066; B. 0,o35 to 0,04 mm. 

 Central nodule large, rounded quadrate. Furrows broad, semilauceolate, crossed by rows of alveoli. 

 Costse 7 in 0,oi mm. Alveoli 9 in 0,oi mm. forming longitudinal rows, parallel with the margins. 

 — Nav. Pelagi A. S. Atl. VII f. 25, 26. 



Marine: Campeachy Bay! Colon (Deby CoU.)! Tahiti! 



Var. nigricans Pant. (1893). — V. narrow elliptical. L. 0,25; B. 0,o7. Transverse and 

 longitudinal rows of alveoli 6 in 0,oi mm. — Nav. nigricans Pant. Ill PL XL f. 552. 



Marine: Bory, Hungary, fossil (Pant.). 



Var. pseudofusca Pant. (1886). — V. nearly orbicular. L. 0,052 to 0,o87; B. 0,037 to 0,o66 

 mm. Costse in the middle 9 at the ends 13 in 0,oi mm. Furrows forming a large rhomboid space- 

 Longitudinal rows of alveoli about 10 in 0,oi mm. — Nav. pseudofusca Pant. I p. 28 PL XIIl f. 109. 



Marine: Hungary, fossil (Pant.). 



Var. norvegica Cl. — L. 0,085 to 0,oi; B. 0,045 to 0,055 mm. Costse and longitudinal rows 

 of alveoli 10 in 0,oi mm. — N fusca A. S. Atl. VII f. 2, 3. 



Marine: North Sea! Hungary, fossil (Deby Coll.)! 



Var. subrectangularis Cl. — V. more or less rectangular. L. 0,85 to 0, 13; B. 0,o37 to 0,o56 

 mm. Costse and longitudinal rows of alveoli 8 in 0,oi mm. — Nav. fusca A. S. Atl. VII f. 4. 

 N Smithii Donk. B. D. p. 6 PL I f. 4. 



Marine: North Sea! Balearic Islands! Sumatra (I)eby Coll.)! 



