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



No axial nor central area on the dorsal side. Longitudinal line closely approximate to the median 

 line. Dorsal striae 6 to 7 in 0,oi mm. coarsely punctate; puncta 7 in 0,oi mm. Ventral side with 

 a row of short striae along the median line and towards the ends of the valve. Ventral striae 

 frequently crossed by a longitudinal line. — A. S. Atl. XXVII f. 46. A. gigantea var. andesitica 

 Pant. II p. 36; III PL XVII f. 243. 



Marine: Gulf of Naples! Java! Japan! S:n Pedro Calif., fossil (Kinker), Campeachy Bay! 

 Pensacola! Colon (Deby Coll.)! Hungary, Bory fossil (Pant.)? 



Var. obscura Cl. — V. in L. 0, lo to 0,20, in B. 0,oi5 to 0,04 mm. Striae on the dorsal 

 side 6 to 7 in 0,oi mm.; puncta coarse, about 5 in 0,oi mm. forming longitudinal undulating lines. 

 Ventral side with a row of short, radiate striae along the whole median line. — A. S. Atl. PL 

 XXVIII f. 20 (without name). Icon. n. PL IV f. 28, 29. ' 



Marine: Balearic Islands! Gulf of Naples (Deby Coll.)! Sumbava (Kinker Coll.)! Sumatra 

 (Deby Coll.)! Macassar Straits! Campeachy Bay (Atl.). 



Forma minor. Striae 8 in 0,oi mm. L. 0, ii mm. — A. S. Atl. XL f. 28, 29. 



Marine: S:t Peter, Hungary (fossil)! Leton Bank (Atl.). 



Var. fusca A. S. (1875). — V. in L. O.o: to 0,i2 mm. Dorsal striae 10inO,oi mm. coarsely 

 punctate; puncta 8 in 0,oi mm. Longitudinal line somewhat obscure. Ventral part broad, struc- 

 tureless, except at the ends, where are short sets of oblique, granulate striae. Zone with irregu- 

 lar small puncta, giving it a brownish colour. — A. fusca A. S. Atl. XXVII f. 68. 



Marine: Gulf of Naples! Red Sea (Van Heurck Coll.)! Java! Labuan! Macassar Straits! 

 Gulf of Mexico (Atl.), Bahia! Galapagos Islands! 



16. A. nodosa Brun. (1891). — V. with strongly arcuate dorsal margin, straight ventral 

 margin and broad, rounded ends. L. 0,i2 to 0, 15; B. 0,o42 mm. Median line slightly biarcuate. 

 Dorsal side without axial and central areas, divided into two parts by a longitudinal line (or 

 crest), of which the interior bears short rows of large puncta, and the exterior strong costae (4 in 

 0,01 mm.) alternating with rows of large ocelli (4 to 5 in 0,oi mm.), which form longitudinal, 

 slightly undulating lines. Ventral side of the valve narrow, with short and strong costae. — 

 D. espfeces nouv. p. 9 PL XII f. 2. 



Marine: Nossibe (Brun Coll.)! Japan (Brun), Samoa! Macassar Straits! 



One of the largest and stoutest forms of Amphora. The strong central nodule, the crest 

 enclosing, on the dorsal side of the valve, a furrow, recal Diploneis, as does also the structure ol 

 transverse costae, alternating with ocelli. 



17. A. Oculus A. S. (1875). — V. lunate, with obtuse ends. L. 0,07 to 0,i5; 0,02 to 0,04 

 mm. Median line approximate to the ventral margin, straight or slightly biarcuate. Axial area 

 indistinct; central area large, rounded. Longitudinal line at a considerable distance from the 

 median line. Striae on the dorsal side 7 to 10 in 0,oi mm., coarsely punctate; puncta about 8 in 

 0,01 mm. Ventral side narrow, with coarse striae in its whole length. — Atl. XXVII f. 52. A. 

 Oc. var. fossilis Pant. I p. 22 PL XIV f. 127. A. Wachenhusenii Janisch A. S. Atl. XL f. 38 (1876). 



Marine: Gulf of Naples (Deby, Brun Coll.)! Seychelles (Van Heurck Coll.)! Sumbava (Kinker 

 Coll.)! China (Deby Coll.)! Japan (Atl.), Campeachy Bay (Atl.). 



Var. Farcimen A. S. (1875). — L. 0,o6 to 0,o7; B. 0,oi9 mm. Central area less distinct. 

 Striae 11 in 0,oi mm.; puncta 10 in 0,oi mm. — A. Fare. A. S. Atl. XXVII f. 56, 57. 



Marine: Seychelles (Van Heurck Coll.)! Samoa (Atl.), Galapagos Islands! Campeachy Bay (Atl.). 



18. A. Schmidtii Grun. (1875). — Frustule in outline elliptical with truncate ends- 

 L. 0,09; B. 0,04 mm. Median line elevated to a biarcuate keel. Dorsal side with coarsely punctate 

 striae, 9 in 0,oi mm. reaching to the median line. Ventral side also with coarsely punctate striae. 

 Zone with two or more longitudinal rows of large puncta. — A. S. Atl. XXVIII f. 2. 



Marine: China! Samoa (Atl.), Bahia, Rio Janeiro, Porto Seguro (Deby Coll.)! 



