KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 26. N:0 2. 31 



Marine: Mediterranean Sea, Alexandria (Deby Coll.)! Levant (Grove Coll.)! Delaware (Lewis) 

 Florida! "West Indies! Colon! Gulf of Mexico! Java (Atl.) Fossil Szakal, S:t Peter, Hungary^ 

 (Pantocsek). 



Var. Janischii Castr. (1886). — Segments elliptic-lanceolate, obtuse. L. 0,i; B. 0,025 to 

 0,03, at the constriction 0,oi5 mm. Marginal cellules 4 to 4, 5 in 0,oi mm. Cellules of the valve 

 10 to 11 in 0,01 mm. Transverse striae 26 to 27 in 0,oi mm. — Navic. Jan. Castr. D. Voyage 

 Challenger p. 29 PI. XXX f. 5. Mastogloia reticulata var. japonica Brun. D. fossiles du Japon 

 p. 72; 1889. Dictyoneis marginata A. S. Atl. CLX f. 17, 18, 19, 21. B. marg. v. Jan. A. S. Atl. 

 CLXXXVIII f. 50. 



Marine: Madagascar (Brun Coll.)! Cebu! Java (Atl.), Japan (Atl.), Samoa (Atl.). Galapagos 

 Islands! Bermudas (Castr.) Florida! Campeachy Bay! Colon (Deby Coll.)! Oamaru fossil, (Atl.) 



Var. Clevei Brun. (1889). — Segments broad, elliptical, with rounded ends. L. 0,ii to 0, 125; 

 B. 0,04 2, at the constriction 0,oi3 mm. Marginal cellules 3 to 4 in 0,oi mm. — Mastogloia Clevei 

 Brun a. Temp. D. foss du Japon p. 39 PL IX f. 18. D. margin, v. Clevei A. S. Atl. CLXXXVIII, 46. 



Marine: Java! Japan fossil and living, (Brun). 



Var. intermedia Cl. — Segments narrow, elliptical. L. 0,12; B, 0,03, at the constriction 

 0,014 mm. Marginal cellules 4 in 0,01 mm. Cellules of the valve 10 in 0,oi mm. Transverse 

 striae 24 in 0,oi mm. — Mastogloia Clevei Brun. A. S. Atl. PI. CLX f. 34, 35. 



Marine: Nossi Be (Brun Coll.)! Japan (Atl.). 



Var. commutata Cl. — V. about 6 times longer than broad, gently constricted in the middle. 

 Segments narrow, elliptical to elliptic-lanceolate. Ends obtuse. L. 0,ii to 0,12; B. 0,02i to 0,025, 

 at the constriction 0,oi to 0,i2 mm. Marginal cellules 5 to 6 in 0,oi mm. Cellules of the valve 

 12 in 0,01 mm. Transverse striae 25 in 0,oi mm. — Dictyoneis marginata f. elongata A. S. Atl. 

 CLX f. 30. 



Marine: Manila (Deby Coll.)! Macassar Straits (Grove Coll.)! Sumbava (Kinker Coll.)! Cam- 

 peachy Bay! Rio Janeiro (Deby Coll.)! 



Var. gigantea Cl. — V. as in the Var. commutata. L. 0,i8; B. 0,044, at the constriction 

 0,022 mm. Marginal cellules 4 in 0,oi mm. Cellules of the valve 9 in 0,oi mm. 



Marine: Oamaru, New Zealand, fossil (Grove Coll.)! 



Var. spectatissima Grbv. (1866). — V. strongly constricted, with cuneate, obtuse segments. 

 L. 0,09 to 0,13; B. 0,03, at the constriction 0,oi3 mm. Marginal cellules broad, 4 in 0,oi mm. 

 Cellules of the valve coarse, 8 in 0,oi mm. Transverse striae 23 in 0,oi mm. — Navic. spectatissima 

 Grbv. T. M. S. Vol. XIV p. 84 PL IX f. 29. Dictyoneis sped. A. S. Atl. CLX f 24 to 26, 32. 



Marine: Zanzibar (Grev.) Seychelles (Van Heurcks Coll.)! Campeachy Bay (Atl.), Campeachy 

 Bank (Atl.). 



4. D. Thumii Cl. (1890). — V. linear-lanceolate, with obtuse ends. L. 0,ii to O.is; B. 0,022 

 to 0,032 mm. Terminal iissures in contrary directions. Marginal cellules 4 to 5 in 0,oi mm., of 

 equal size. Cellules of the valve about 11 in 0,oi mm. Transverse striae 24 to 25 in 0,oi mm. — 

 Cl. Diatomiste I p. 16. Icon. n. PL V f. 33. A. S. Atl. CLXXXVIII f. 44, 45. 



Marine: Red Sea (Atl.) Seychelles (Van Heurck Coll.)! Java! Cebu! China! Brazil. (Atl.). 



D. Thumii. is nearly akin to D. marginata var. commutata. The fig. 31 PL CLX and fig. 

 49 PL CLXXXVIII in A. S. Atl. seem to represent intermediate forms, as also Pseudodictyoneis 

 Pant. Ill PL I f 8. 



5. D. subeonstricta Cl. N. Sp. — V. slightly constricted, with broad, elliptic-lanceolate 

 segments. L. 0,05 5 to 0,083; B. 0,024 to 0,03, at the constriction 0,oi8 mm. Marginal cellules 4 

 in 0,01 mm. Cellules of the valve 9 in 0,oi mm. Transverse striae 23 in 0,oi mm. — PL V f . 31. 



Marine: Madagascar! Cebu! Campeachy Bay! 



This form is nearly akin to D. marginata var. Janischii and is perhaps more correctly to 

 be appreciated as a less constricted form of this variety. 



