KONGL. 8V. VKT. AKADEMIENS IIANI)M\(;AI{. ISAM) 27. Mo 3. 187 



Artificial ley. 



I L. 0,03 to 0,05 mill A. jmsUla Cl. 



\ L. 0,04r) to 0,07.-. mm 2. 



.^ ( Central nodule stauroid A. scndaiana Brun. 



"' \ — — not — 3. 



., I Valve constricted in the middle f). 



■ \ — not — — — 4. 



j Costae 8 to 9 in 0,oi mm A. formosa Cu. 



■ \ — 5 to G — — A. Srala (U,. a. Grove. 



I Slightly constricted (J. 

 Strongly — 7. 

 Trieonstricted A. dorsalia Ol. a. Grovk. 



Valve with a hyaline wing A. limhata Ol. a. Grove. 



ithout — — A. Grovei Cl. 



Stria; 8 in 0,oi mm A. Ccutielus Cl. a. Grove. 



10 — — A. hiconvexa Jan. 



I Valve wit 

 •'• 1 - wit 



1. A. pusilla (Greg. 1857?) Cl. — Frustule linear-elliptical, with rounded end.s. L. 0,or,2 

 to 0,0.53; B. 0,01 to 0,02 mm. V. with obtuse and gibbous ends. Median line biarcuate, at some 

 distance from the ventral margin. Dorsal side striate; strife 12 in 0,(ji mm. not distinctly punc- 

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

 PI. XXIII f. 3, 4. 



Marine: Macassar Straits! 



It is doubtful what A. ^;»^^<7Za Greg, may denote. It is described as having coarser striae 

 (9 in 0,01 mm.) than A. bacillaris 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 have hitherto seen, no distinct longitudinal line. 



2. A. Camelus Cl. and Grove (1892). — Frustule of rectangular outline. L. 0,07.3; B. 0,0,3.') 

 mm. Zone with a number of longitudinal divisions (2 in 0,01 mm.) transver.sely striate; striae 9 

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

 Ends capitate. Dorsal side with 8 striffi in (),oi mm. — Diatomiste I p. 158 PI. XXII f. 9 to 12. 



Marine: Macassar Straits! 



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

 the middle, and with rostrate-truncate or capitate ends. L. 0,i to 0,14; B. 0,017 to 0,o2.'-> mm- 

 Median line straight, approxim.ate to the ventral margin. Dorsal stria; 9 to 11 in 0,oi mm. alter- 

 nating with single rows of obscure puncta, about 18 in 0,oi mm. Ventral side without strict. — 

 A. S. Atl. XXV f. 08. 



Marine: Macassar Straits (Grove Coll.)! Nossibe (Brim Coll.)! Carpentai'ia 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 strife of the dorsal side are 

 often approximate, giving the appearance of a stauros. 



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

 with a number of longitudinal divisions (about 3 in 0,oi mm.) transversely and coarsely sti'iate; 

 V. with capitate ends and qnadri-undulated dor.sal margin. Striae 10 in 0,oi mm. Diatomiste I 

 p. 158 PL XXII f. 13 to 15. 



Marine: Macassar Straits! 



This .species seems to be akin to A. nvdnhda Grev. (Ed. N. Phil. J. XVII p. 182 f. 3 18(53) 

 from Queensland. The latter has however much coarser strife and a not complex zone. 



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

 in the middle. L. (),o4.'i to 0,(i7fi; B. 0,02 to 0,035 mm. Zone with several longitudinal divisions 



Konffl. Sv. Vet. Akad. Hnudl Hand Ti . i\:o 3. 18 



