KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 137 



Ärtificial Jcey. 



^ 111. 0,03 to 0,05 mm A. piisilla Cl. 



\L. 0,045 to 0,075 mm 2. 



„ J Central nodule stauroid A. semdaiana Beun. 



t — — not — 3. 



„ J Valve constricted in tlie middle 5. 



^- \ _ not - - - 4. 



. ( Costse 8 to 9 in 0,01 mm A. formosa Cl. 



' \ — 5 to 6 — — A. Scala Cl. a. Gkove. 



{SligMly constricted 6. 

 Strongly — 7. 

 Triconstricted A. dorsalis Vh. a. Grove. 



„ J Valve with a liyaline wing A. Kmbata Cl. a. Grove. 



( — withoat — — A. Grovei Cl. 



_ , Strise 8 in 0,oi mm A. Camelus Cl. a. Geove. 



10 — — A. biconvexa Jan. 



{" 



1. A. pusilla (Greg. 1857?) Cl. — Frustule linear-elliptical, with rouiidecl ends. L. 0,o32 

 to 0,053; B. 0,0 1 to 0,02 mm. V. with obtnse and gibbous ends. Median line biarcuate, at some 

 distance from the ventral margin. Dorsal side striate; strite 12 in 0,oi mm. not distinctly punc- 

 tate. Ventral side not striate. — D. of Clyde p. 525 Pl. XIV f. 95? Diatomiste I p. 159 



pi. xxni f. 3, 4. 



Marine: Macassar Straits! 



It is donbtful what A. pusUla Greg. niay denote. It is deseribed as having coarser strise 

 (9 in 0,01 mm.) than A. hacillaris Greg., to which it otherwise bears a considerable resemblance. 

 There is some doubt about the exact position of this little form, as the ventral side of the valve 

 has, so far as I liave hitherto seen, no distinct longitudinal line. 



2. A. Caniehis Cl. and Grove (1892). — Frustule of reetangnlar ontline. L. 0,n-3; B. 0,03.5 

 mm. Zone with a nnmber of longitudinal divisions (2 in 0,oi mm.) transversely striate; strise 9 

 in 0,01 mm. V. with slightly arcuate median line and the dorsal margin sinnose in the middle. 

 Ends capitate. Dorsal side with 8 stripe in 0,oi mm. — Diatomiste I p. 158 Pl. XXII f. 9 to 12. 



Marine: Macassar Straits! 



3. A. biconvexa Jan. 1875. — V. with straight ventral margin. Dorsal margin siniiose in 

 the middle, and with rostrate-truncate or capitate ends. L. O, i to 0, 14; B. 0,oi7 to 0,o2 5 ram. 

 Median line straight, approximate to the ventral margin. Dorsal striai 9 to 11 in 0, 01 mm. alter- 

 nating with single rows of obscnre pnncta, abont 18 in 0,oi mm. Ventral side without strite. — 

 A. S. Atl. XXV f. 68. 



Marine: Macassar Straits (Grove Coll.)! Nossibé (Brun Coll.)! Carpentaria Bay (Atl.). 



This form, of which valves only have been observed, is still imperfectly known, and its 

 place in the system is consequently not well established. The median striee of the dorsal side are 

 often approximate, giving the appearance of a staiiros. 



4. A. dorsalis Cl. and Grove (1892). — Frustixle reetangnlar. L. 0,09; B. 0,o3 mm. Zone 

 with a nnmber of longitudinal divisions (about 3 in 0, 01 mm.) transversely and coarsely striate; 

 V. with capitate ends and quadri-nndulated dorsal margin. Strise 10 in 0, 01 mm. — Diatomiste I 

 p. 158 Pl. XXII f. 13 to 15. 



Marine: Macassar Straits! 



This species seems to be akin to A. undulata Grev. (Ed. N. Phil. J. XVII p. 182 f. 3 1863) 

 from Queensland. The latter has however mnch coarser strise and a not coniplex zone. 



5. A. limbata Cl. and Grove (1892). — Frustule in outline reetangnlar, slightly constricted 

 in the middle. L. 0,045 to 0,075; B. 0,02 to 0, 035 mm. Zone with several longitudinal divisions 



Kongl. Sv. Vet. Akad. Handl. Baud 27. N:o 3. 18 



