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



'I. A. gibba A. S. (187(>). — V. rectangular, somewhat constricted in the middle. L. 0,03; 

 B. 0,0 15 mm. i\[edian line clo.se to the ventral margin. No areas and no longitudinal line. Strife 

 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. 



]\Iarine: Ualapagos Islands! Campeachy Bay (Atl.). 



This is a characteristic and easily recognized form, e\'iilently akin to A. lieichardtiana. As 

 entire frustules ai"e 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. corpuJrnta. 



o. A. Reichardtiailsi (tIrun, (1867). — V. linear with broad, rounded ends. L. 0,04 to 0,07; 

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

 Strife slightly radiate, punctate, 10 in 0,01 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. 0,057 ; B. 0,(ii 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. Stritc 10 in 0,oi mm. — Diatoraiste II p. 5(3 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, 10 to 0, le; B. 0,o4 mm. Zone 

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

 line very excentric, slightly biarcuate (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 

 0,01 mm.). Spaces between them \Qvy narrow, forming longitudinal undulating lines. Longi- 

 tudinal striffi 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 Traclnpicis. 



(). A. Wittsteinii A. S. (l.S7(j). — Frustule rectangular, with lai^ge, hyaline Hmbus. L. 0,o5 8 

 to 0,onr); 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 stritXi in 

 0,01 mm. — Atl. XXXIX f. (i. 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. Striee 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.). 



S. A. labueiisis Cl. (1883). — Frustule rectangular, with parallel margins. L. 0,o6; 

 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,o 1 nun. Transverse striae 6 in 0,oi mm. finely 

 transversely lineate. — Vega p. 493 PI. XXXV f. 1. A. Jah. var. fiisiforniis IjEud. Fortm. D. de 

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



Marine: Labuan! 



