136 P. T. CLEVE, SYNOPSIS OE THE NAVICULOID DIATOMS. 



Var. ineurvata Brun (1891). Val ve arcuate. L. 0,i to 0,i3; B. 0,oii mm. Strise 6 in 0,oi 

 mm. — A. lanceolata var. incr. Brun D. espéces n. p. 8 Pl. XII f. 3. 



Marine: Japan! "Western Africa (Brun). 



Var. sebrina A. S. (1875). — V. gibbous in the middle. L. 0,o"5; B. 0,oo9 mm. Strise C^ 

 (dorsal) to 7 (ventral) in 0,oi mm. — A. zehrina A. S. Atl. XXV f. 11. 



Marine: Baltjik Dept. (Atl.). 



2. A. cymbiformis Cl. N. Sp. — V. semilanceolate, acute. L. 0,o4.5 to 0,07; B. 0,on7 to 

 0,0 13 mm. Axial area indistinct. Strise 14 to 17 in 0,oi mm. — A. S. Atl. Pl. XXV f. 9. 



Marine: Port Jackson! Labuan! 



3. k. cymbelloides G-run. (1867). — Hyaline. L. of the frustule 0,o38 to 0,o84; B. of the 

 frustule 0,011 to 0,oi3, of the valve 0,oo8 to 0, 011 mm. Strire very fine, 29 in 0,oi mm. or more. 

 — Hedw. 18(i7, VI p. 24. A. migustu var. miniita GuuN. A. S. Atl. XXVI f. 65, 66. Dannp. 

 Baltic D. Pl. I f. 10? A. angusta var. glaherrima Grun. A. S. Atl. XXVI f. 61, 62. 



Marine: Seychelles! Honduras (Grun.), Barbados! 



The original A. cymhelloides of Grunow is a very delicately striate form, of which the 

 author several years ago sent me a sketch, agreeing with A. angusta var. oninuta, or rar. glaherrima 

 in A. S. Atl. More coarsely striate forms have since been published as A. cymhelloides (Atl. XXV 

 f. 8, 14) which belong to A. angusta. The var. mauritiana Grun. (Hedwigia 1. c. p. 25) cannot 

 belong to the same species as it has a longitudinal line across the strise. 



4. A. arcta A. S. (1875). — Hyaline. Frustule almost linear with truncate ends. L. 0,094; 

 B. 0,012 mm. Strige delicate. — Atl. XXVI f. 63. 



Marine: Australia, Port Lincoln (Atl.). 



5. A. magellanica Petit (1888). — V. semilanceolate, acute. L. O.oei to 0,o63; B. 0, 01 to 

 0,011 mm. Median line straight, approximate to the ventral margin. Axial area indistinct; central 

 small, i'0unded. Strise 12 in 0,oi mm. finely punctate. — D. de Cape Horn p. 119 Pl. X f. 14. 

 A. S. Atl. XXV f. 4 (no name). 



Marine: Magellan's Straits! 



6. A. bituniinosa Pant. (1889). — Frustule elongated, elliptical. L. 0,oi6 to 0,043; B. 0, 01 2 

 to 0,014 mm. Median line approximate to the ventral margin, .slightly biarcuate. Axial and 

 central areas indistinct. Strise 14 to 15 in 0,oi mm. not distinctly punctate and not interrupted 

 or crossed by a longitudinal line. Connecting zone not complex. — Pant. II p. 35 Pl. I f. 1, 

 Pl. II f. 23. 



Brackish water: Szardoc, Hungary, fossil! 



It is doubtful whether this species be correctlj^ plaoed in this subgenus or in the subgenus 

 Amphora, as the median line is not perfectly straight. 



Subgenus Calamphora Cl. 



Frustule rectangular, with more or less rounded ends. Zone complex, with more or less 

 numerous, transversely striate or costate divisions. Valves linear, obtuse, or witii obliquely 

 rounded ends. Median line biarcuate, not closely approximate to the ventral margin. Dorsal side 

 witli transverse strise, not crossed by a longitudinal line. Ventral side structureless, bnt with 

 a longitudinal line. 



This suligenus comprises (komplex forms, the dorsal stria- of wliich are not crossed by a 

 keel or line. Fi'oin Halumphnra and Oxyamphora they differ by the broader ventral side, which 

 has a longitudinal line, and by the nou-protracted or luin-rdsfrate ends. 



