KONGL. SV. VET. AKADEMIENS HANDI.INfi A 1{. BAND 27. N:() 3. 115 



Var. maxima Cl. a. (tKOve (lHit2). — L. of V. 0,13 to 0, 1 1; ; H. 0,02 to (),(»:', uiin. Strin' 8,5 

 to 4,5 in 0,01 mm. — Diatomi.ste I p. 156 PI. XXII f. 1 to 4. 



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



Var. ciirffi Cl. — L. of V. 0,o(i8 to 0,093; B. 0,oi7 to 0,024 mm. Stria- 5 in 0,oi mm. 

 — A. areolata Grun. A. S. Atl. XXXIX f. 28. A. megapora Pant,, II p. ;58 PI. XXIX 

 f. 418 (1889). 



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



Var. minor Cl. — L. of V. 0,o8 to 0, 1; B. 0,oi7 mm. StricB 5 to (),:> in 0,01 ram. 



Marine: Java! Porto Seguro (Deby Coll.)! Colon (Deby Coll.)! Pensacola (Cl. M. D. N:o ;'.20). 



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

 B. 0,0 3 mm. Zone with distant longitudinal rows of puncta. V. with arcuate dorsal, and centrally 

 gibbous ventral, margins. Ends rostrate and reflexed. B. 0,o7 mm. Median line near the ventral 

 margin. Axial area very narrow. Central nodule incrassate on the dorsal side. Strise 10 inO,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 constructed from the iigures in 

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



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

 truncate ends, indented in the middle. L. 0,08; B. 0,027 mm. Zone with about 3 divisions in 0,o 1 

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

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

 nodule incras.sate but not dilated into a stauros. Above the nodiile is an oblong depression. Axial 

 area narrow, dilated around the central nodule. Longitudinal line di.stinct. Stria' 11 in 0,oi mm. 

 of distant but obscure pnncta. Ventral side narrow; striae 12 in O.oi mm. — Atl. XXV f. 51, 52, 

 53, 5(1 ; XL f. 30, 32. H. L. Sm, T. N:o 32. A. rontracfa Grun. A. S. Atl. XXV f. 54, 55, 57. 



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

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



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

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

 striiv. 10 to 11 in 0,oi 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. Strife 9 to 10 in 0,oi mm., 

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

 PI. il f. 11. A. S. Atl. XXV f. 61? 



Marine: Norway Grip (valve not winged)! Morocco! Balearic Islands! Macas.sar Straits! 



Var. major Cl. — L. 0,09 mm. Strite distinctly punctate, 8 in 0,oi mm. 



Marine: Galapagos Island! 



Var. aptera Cl. — L. 0,o.^ mm. Dorsal side without limbus. Strite 12 in O.oi mm. 



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



27. A. 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 0,0 1 mm. transversely striate; stria; 

 10 in 0,01 mm. V. narrow, linear with broad, capitate and incurved ends. L. 0.09 to 0,13; 

 B. 0,0 14 to 0,02 mm. Central nodule transversely dilated into an obscure stauros. Axial and 

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

 7 to 9 in 0,0 1 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 stritii (specimen from 

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



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



