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



2. A. gibba A. S. (1876). — V. rectangular, somewhat constricted in the middle. L. 0,03; 

 B. 0,015 mm. Median line close to the ventral margin. No areas and no longitudinal line. Striae 

 transverse in the middle, radiate at the ends, about 8 in 0,oi mm., composed of distant puncta 

 about 6 in 0,oi mm. — Atl. XXXIX f. 32. 



Marine: Galapagos Islands! Campeachy Bay (Atl.). 



This is a characteristic and easily recognized form, evidently akin to A. Keichardtiana. As 

 entire frustules are unknown, and the ventral side of the valve not has been seen, it is impossible 

 to decide its place in the system. In the striation it resembles of A. corpulenta. 



3. A. Reichardtiana Grun. (1867). — V. linear with broad, rounded ends. L. 0,04 toO,o7; 

 B. 0,01 to 0,02 mm. Median line close to the ventral margin. No areas and no longitudinal line. 

 Strise slightly radiate, punctate, 10 in 0,oi mm. — Hedwigia VI p. 25. A. S. Atl. XXXIX f. 33, 34. 



Marine: Adriatic! Cape of Good Hope! Campeachy Bay! Pensacola! 



An easily recognized form, but too imperfectly known to be placed in any of the larger 

 sections of Amphora. 



4. A. scabriuscula Cl. a. Grove (1893). — V. lunate, obtuse. L. 0,o.'i7; B. 0,oi mm. Dorsal 

 side with rather broad axial area, without longitudinal line. Structure coarse and transversely 

 lineate alveoli, arranged in somewhat radiate rows, 10 in 0,oi mm. Ventral side throughout 

 striate. Striae 10 in 0,oi mm. — Diatomiste II p. 56 PI. Ill f. 7. 



Marine: Macassar Straits! 



This species is evidently nearly akin to the genus Trachyneis. 



5. A. Clevei Grun. (1875). — Frustule rectangular. L. 0,io to 0, le; B. 0,04 mm. Zone 

 not complex. V. linear-lanceolate or (according to the position) semilanceolate and rostrate. Median 

 line very excentric, slightly biarcaate (or according to the position of the valve, straight, and close 

 to the margin). Central nodule on the dorsal side a short stauros, expanding outwards, on the 

 ventral irregularly rounded. Axial area narrow, linear on the dorsal side. Central area of the 

 outline of the central nodule. Alveoli in almost transverse or slightly curved rows (8 to 9 in 

 0,0 1 mm.). Spaces between them very narrow, forming longitudinal undulating lines. Longi- 

 tudinal strise very fine. — A. S. Atl. XXV f. 46 to 48. 



Marine: North Carolina! Florida! West Indies! 



This peculiar form is an Amphora with the characteristics of Trachyneis. 



6. A. Wittsteinii A. S. (1876). — Frustule rectangular, with large, hyaline limbus. L. 0,o58 

 to 0,065; B. 0,023 mm. Zone complex, on the ventral side with 6 to 7, on the dorsal with 4, divi- 

 sions in 0,01 mm. Dorsal divisions punctate; puncta 10 in 0,oi mm. V. narrow, with 7 striae in 

 0,01 mm. — Atl. XXXIX f. 6, 7. 



Marine: ? 



This is a characteristic form, of which no detached valves have been examined. It is there- 

 fore impossible to decide as to its place in the system. It may belong to the subgenus Calamphora. 



7. A. Miilleri A. S. (1875). — V. almost linear, subacute. L. 0,075; B. 0,oo9 mm. Median 

 line almost straight. Dorsal side with a pretty broad axial area. Striae 8 in 0,oi mm., short, 

 coarsely granulate. Ventral side with a row of puncta along the margin. — Atl. XXVI f. 31. 



Marine: North Sea (Atl.). 



8. A. labuensis Cl. (1883). — Frustule rectangular, with parallel margins. L. 0,06; 

 B. 0,02 mm. Zone not complex. Components of the median line divergent from the central nodule 

 to the corners of the frustule. V. linear, in B. 0,oi mm. Transverse striae 6 in 0,oi mm. finely 

 transversely lineate. — Vega p. 493 PL XXXV f. 1. A. lab. var. fusiformis Leud. Fortm. D. de 

 la Malaisie p. 11 PL I f . 8 (1892)? 



Marine: Labuan! 



