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



8. A. aspera Petit (1877). — V. .semilanceolate. L. (),or)7 to Oosf); B. O.ois to 0,oi8 mm. 

 Ventral margin straiglit, .somewhat gibbou.s in the middle. (Jentral nodule .strong. I)or.sal side 

 with 16 stricB in 0,oi mm. composed of distant (about 10 in 0,01 mm.) puneta, forming undulate, 

 longitudinal lines. Ventral side narrow, finely striate. Strife 22 to 23 in 0,oi mm — D. de I'ile 

 Campbell p. 19 PI. IV f. 9. Icon. n. PI. Ill f. 'I'l. A. uvdatu Leud. Fortm. D. de la Malaisie 

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



Marine: (iulf of Naples (Deby Coll.)! N. Zealand (Petit). 



9. A. j^roeiilaiulica 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. StritE of the dorsal side 14 (at the ends 15 to IG) inO,oi mm. composed 

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

 stricE in 0,oi mm. — PI. IV f. 1. 



Marine: Davis Strait! 



10. .4. acuta Greg. (1857). - Frustule subquadrate. Divisions of the zone about 4 in 0,oi 

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

 gin, straight ventral margin and apiculate ends. L. 0,o89 to 0,ir>; B. 0,u.3 mm. Central nodule 

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

 puneta, about 10 in 0,oi mm., forming undulating, longitudiiml 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! Fiumark! North Sea! Morocco! Mediterranean Sea! China! 

 Magellan's Strait! 



Var. neoffcna Pant. (1889). — L. 0,o84 to 0,092; B. 0,oi8 to 0,o2 mm. Striae 17, .5 in 0,oi 

 mm. — Pant. II p. 35. 



Marine: Hungarj', Bory fossil (Pant.). 



Var. arcuata A. S. (1875). — V. with recurved ends. L. 0,oo to 0,15; B. 0,012 to 0, 028 mm. 

 Dorsal strife 9 to 12 in 0,oi mm., composed of distant puneta (about 7 in 0,oi mm.). Ventral 

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



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

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



Var. lahi/rinthica Grun. (1880). — V. in L. 0, 1 to 0, is. Dorsal striae 14 to 17 in 0,oi mm., 

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

 mm. — A. lahyr. Grun. A. D. p. 25. Icon. n. PI. IV f. 23. 



Marine: Balearic Islands! 



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



A. nohiJis, which seems to represent an entire fi'ustule of A. acuta. 



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

 ventral margin. Ends apiculate. L. 0,12; B. 0,o28 mm. Median line approximate to the ventral 

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

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

 Ventral side very narrow; its strife close, about 26 in O.oi mm. — Atl. XXVI f. 18. Icon. n. 

 PI. IV f. 7—9. 



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



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

 as long as broad. Zone with numerous divisions. V. lunate with acute ends. L. 0,o.') to 0,17; 



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

 transverse stauros. Dorsal side with very oblique stria;, about 17 in 0,oi mm., turned in opposite 

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



