128 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



8. A. aspera Petit (1877). — V. semilanceolate. L. 0,057 to O, oss; B. 0,oi3 to O.ois mm. 

 Ventral margin straight, somewhat gibbous in the middle. Central nodule strong. Dorsal side 

 witb 16 strise in 0,oi mm. composed of distant (about 10 in 0,oi mm.) pnncta, forming unduiate, 

 longitudinal lines. Ventral side narrow, finely striate. Strise 22 to 23 in 0,oi mm — D. de Tile 

 Campbell p. 19 Pl. IV f. 9. Icon. n. Pl. III f. 22. A. undata Leud. Fortm. D. de la Malaisie 

 p. 11 Pl. II f. 1 (1892). 



Marine: Gulf of Naples (Deby CoU.)! N. Zealand (Petit). 



9. A. groeiilandica Cl. N. Sp. — V. narrow, lunate, with subacute ends. L. 0,o9; B. 0,oi 6 

 mm. Ventral margin straight. Median line approximate to the ventral margin. Central nodule 

 not transversely dilated. StriiB of the dorsal side 14 (at the ends 15 to 16) inO,oi mm. composed 

 of puncta (12 in 0,oi mm.) forming slightly undulating, longitudinal rows. Ventral part with 23 

 strise in 0,oi mm. — Pl. IV f. 1. 



Marine: Da vis Strait! 



10. A. acuta Greg. (1857). -- Frustule subquadrate. Divisions of the zone about 4 in O, o i 

 mm. iinely transversely striate; strise about 21 in 0,oi mm. V. lunate, with arcuate dorsal mar- 

 gin, straight ventral margin and apiculate ends. L. 0,089 to 0,i5; B. 0,o.3 mm. Central nodule 

 transversely dilated into a stauros. Strise on the dorsal side 12 to 14 in 0,oi mm., composed of 

 puncta, about 10 in 0,oi mm., forming undulating, longitudinal rows. Ventral side very narrow, 

 finely striate; strise about 26 in 0,oi mm. — D. of Clyde p. 524 Pl. XIV f. 93. A. S. Atl. 

 XXVI f. 19, 20 (21, 22?). 



Marine: Greenland! Spitsbergen! Finmark! North Sea! Morocco! Mediterranean Sea! China! 

 Magellan's Strait! 



Var. neogena Pant. (1889). — L. 0,084 to 0,092; B. 0,oi8 to 0,02 mm. Strise 17,5 in 0,oi 

 mm. — Pant. II p. 35. 



Marine: Hungary, Bory fossil (Pant.). 



Var. arcuata A. S. (1875). — V. with recurved ends. L. 0,06 to 0,is; B. 0,oi2 to 0, 028 mm. 

 Dorsal strise 9 to 12 in 0, 01 mm., composed of distant puncta (about 7 in 0, 01 mm.). Ventral 

 strise very close. — A. arcuata Atl. XXVI f. 27 to 29. 



Marine: Balearic Islands! Seychelles (Van Heurck CoU.)! Macassar Straits (Grove CoU.)! 

 Samoa (Atl.), Mazatlan (Atl.), Gulf of Mexico (Atl.). 



Var. labyrinthica Grun. (1880). — V. in L. 0,i to O, i.s. Dorsal strise 14 to 17 in 0, 01 mm., 

 composed of distinct puncta (10 in 0,oi mm.) forming undulating lines. Ventral strise 26 in 0, 01 

 mm. — A. labyr. Grun. A. D. p. 25. Icon. n. Pl. IV f. 23. 



Marine: Balearic Islands! 



In the Diatoms of Clyde Greg. has 1857 figured (p. 521 Pl. XIII f. 87) a form, named 



A. nobilis, which seems to represent an entire frustule of A. acuta. 



11. A. micans A. S. (1875). — V. hyaline, with strongly arcuate dorsal margin and straight 

 ventral margin. Ends apiculate. L. 0,12; B. 0, 028 mm. Median line approximate to the ventral 

 margin. Central nodule dilated into a stauros. Dorsal strise 14 in 0, 01 mm., distinctly visible 

 near the median line, but on the valve broken up into small, scattered puncta, 4 to 5 in 0, 01 mm. 

 Ventral side very narrow; its strise close, about 26 in 0, 01 mm. — Atl. XXVI f. 18. Icon. n. 

 Pl. IV f. 7—9. 



Marine: Campeachy Bay (Atl.), Macassar Straits (Grove CoU.)! 



12. A. decussata Grun. (1867). — Frustule tliin, elliptical with truncate ends, about twice 

 as long as broad. Zone with numerous divisions. V. lunate with acute ends. L. O, os to 0,17; 



B. 0,011 to 0,03 mm. Median line close to the ventral margin. Central nodule dilated into a 

 trausverse stauros. Dorsal side with very oblique strise, about 17 in 0,oi mm., turned in opposite 

 directions from the stauros and crossed by undulating, narrow, trausverse blank bands. Ventral 



