KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 115 



Var. maxima Cl. a. Grove (1892). — L. of V. O, is to 0,i6; B. 0,o2 to 0,o3 mm. Strise 3,5 

 to 4,.5 in 0,01 mm. — Diatomiste I p. 156 Pl. XXII f. 1 to 4. 



Marine: Tamatave (Kiiiker CoU.)! Sumbava (Kinker CoU.)! Macassar Straits (Grove Coll.)! 



Var. curta Cl. — L. of V. 0,o68 to 0,093; B. 0,oi7 to 0,o24 mm. Strise 5 in 0,oi mm. 

 — A. areolata Geun. A. S. Atl. XXXIX f. 28. A. megapora Pant,, II p. 38 Pl. XXIX 

 f. 418 (1889). 



Marine: Campeachy Bay (Atl.), Hungary, fossil (Pant.). 



Var. minor Cl. — L. of V. 0,o8 to 0,i; B. 0,oi7 mm. Strise 5 to 6,5 in 0, 01 mm. 



Marine: Java! Porto Seguro (Deby CoU.)! Colon (Deby Coll.)! Pensacola (Cl. M. D. N:o 320). 



24. A. capensis A. S. (1875). — Frustule elliptical witb broad, rostrate ends. L. 0,o6; 

 B. 0,03 mm. Zone vpith distant longitudinal rows of puncta. V. with arcuate dorsal, and centrally 

 gibbous ventral, margins. Ends i'ostrate and reflexed. B. 0,0 7 mm. Median line near the ventral 

 margin. Axial area very narrow. Central nodule incrassate on the dorsal side. Striee 10 in 0,oi 

 mm. coarsely punctate. — Atl. XXV f. 49, 50. 



Marine: Cape of Good Hope (Atl.). 



I have not seen this species, and the diagnosis has been o-onstructed from the figures in 

 the Atlas. It seems to be akin to A. Jamschii. 



25. A. Jaiiischii A. S. (1875). — Frustule broad, elliptic-linear, with rostrate and broadly 

 truncate ends, indented in the middle. L. O, os; B. 0, 027 mm. Zone with about 3 divisions in 0, 01 

 mm. coarsely striate; strise about 10 in 0, 01 mm. V. with arcuate dorsal, straight or centrally 

 gibbous ventral, margins and rostrate, reflexed ends. Median line near the ventral margin. Central 

 nodule incrassate but not dilated into a stauros. Above the nodule is an oblong depression. Axial 

 area narrow, dilated around the central nodule. Longitudinal line distinct. Strise 11 in 0, 01 mm. 

 of distant but obscure puncta. Ventral side narrow; strise 12 in 0, 01 mm. — Atl. XXV f. 51, 52, 

 53, 56; XL f. 30, 32. H. L. Sm. T. ]Sr:o 32. A. contracta Grun. A. S. Atl. XXV f. 54, 55, 57. 



Marine: Leton Bank! Seychelles (V. Heurck Coll.)! Campeachy Bay (Atl.), Barbados (Cl- 

 M. D. ]Sf:o 118), Yokohama (Atl.), Macassar Straits! 



26. A. alata Perag. (1881). — Frustule rectangular, indented in the middle. L. 0,o6 to 

 0,07; B. 0,04 mm. Zone with numerous divisions, about 4 in 0,oi mra., transversely striate; 

 stricB 10 to 11 in 0, 01 mm. Hyaline limbus distinct in the middle of frustule. Valve narrow, 

 with capitate, inflected ends. Median line close to the ventral margin. Axial area distinct. 

 Central nodule not dilated to a stauros. Longitudinal line distinct. Strise 9 to 10 in 0, 01 mm., 

 finely punctate. Ventral side structureless, with a longitudinal line. — D. de Villefranche p. 41 

 Pl. II f. 11. A. S. Atl. XXV f. 61? 



Marine: Norway Grip (valve not winged)! Morocco! Balearic Islands! Macassar Straits! 



Var. major Cl. — L. 0, 09 mm. Striee distinctly punctate, 8 in 0, 01 mm. 



Marine: Galapagos Island! 



Var. a.ptera Cl. — L. 0,0.5 mm. Dorsal side without limbus. Strise 12 in 0, 01 mm. 



Marine: Pensacola (Cl. M. D. N:o 320). 



27. Å. vetusta Cl. — Frustule in outline broadly linear elliptical, indented in the middle. 

 L. 0,075; B. 0,03 mm. Zone with 4 longitudinal divisions in 0, 01 mm. transversely striate; strise 

 10 in 0,01 mm. V. narrow, linear with broad, capitate and incurved ends. L. O.09 to 0,13; 

 B. 0,014 to 0,02 mm. Central ftodule transversely dilated into an obscure stauros. Axial and 

 central areas indistinct. Longitudinal line strong, at some distance from tbe median line. Strise 

 7 to 9 in 0,01 mm., transverse and coarsely, but obscurely punctate. Ventral side with a longi- 

 tudinal line (specimen from S:ta Monica) or a longitudinal row of short strise (specimen from 

 Oamaru). Otherwise structureless. — Pl. IV f. 30, 31, 32. 



Marine: Oamaru, New Zealand, fossil (Grove CoU.)! S:ta Monica, Calif. (Deby CoU.)! 



I 



