102 p. T. CLEVE, SYNOrSIS OF THE NAVICULOID DIATOMS. " 



1. A. behringeiisis Cl. N. Sp. — Frustule elliptical, witli truncate ends. L. 0,o28; H. (),oi4 

 mm. V. Innate, acute. L. 0,o28; B. 0,«06 mm. Median line nearly straight. Axial area of the 

 dorsal side broad. Ventral side not striate, very narrow. Dorsal stria? 15 to 1(! in O.oi mm. not 

 crossed by a longitudinal line. — PI. Ill f. 34, 35. 



Marine: Behring Island! 



This small species seems to connect this group with the Cymbamphora. 



2. A. Ovum Cl. N. Sp. — Frustule broadly elliptical, very convex. L. 0,o4; B. 0,025 mm. 

 Median line nearly straight, approximate to the ventral margin. Axial area on the dorsal side 

 not distinct. Striai on the dorsal side 10 to 11 in 0,oi mm. composed of obscure granules and 

 not crossed by a longitudinal line. Ventral side narrow, structureless. — A. S. Atl. XXVI f. 40 

 (without name). Icon. n. PL IV f. 12. 



Marine: Balearic Islands! Java (Atl.). 



3. A. (lubia (Greg. 1857?) A. S. (1875). — Frustule in outline elliptical. L. 0,o4 to 0,o8; 

 B. 0,0 If, to 0,02 mm. Zone very narrow. V. angularly bent along a line combining the ends, so 

 that it, if seem from the end, appears composed of two laminae in an angle of about (iO . Outline 

 of the valve lunate, with arcuate exterior, straight interior margins and acute ends. Median line 

 straight, approximate to the ventral margin. Axial area moderately broad on the dorsal side of 

 the median line. Ventral part of the valve linear, narrow, without stria? and longitudinal line. 

 Dorsal side strongly transversely striate, especially on the exterior part. Stri;e 10 in 0,oi mm. 

 coarsely punctate; puncta 12 in 0,oi mm. — D. of Clyde p. 514 PI. XIII f. 76? A. S. Atl. XXVII 

 f. 20 to 26. Icon. n. PI. IV f. 5, 0. 



Marine: Coasts of Norway! Balearic Islands! Barcelona! Adriatic! Campeachy Bay (Atl.), 

 Singapore (Atl.), Java! 



A. (lubia of Gregory seems to be some species of Amphora in the state of division, scarcely 

 the very characteric and isolated species, figured in Atlas. The form of the valve is generally 

 difficult to make out, but I succeded with the aid of slides, moiinted, by Mr Thum in which the 

 valves were placed on their extremities. They presented tliemselves like segments of an orange. 

 There is no species akin to A. dubia. 



4. A. valida Perag. (1888). — Frustule broadly elliptical, with rounded ends. L. 0,o7 to 

 0,0 8 mm. Valve broadly lunate. Median line ap})roximate to the ventral margin. Axial area on 

 the dorsal side indistinct. Ventral side not striate. Dorsal side with 5 to (> coarsely punctate 

 stri;c in 0,oi mm. — D. Villef. p. 40 PI. Ill f. 25. 



Marine: Villefranche, Medit. (Perag.). 



This species, unknown to me, has the form of A. Ovnm but is much larger. 



5. A. Weiiiekii Jan. (1876). — Frustule rectangular, with parallel margins. L. 0,oti; 

 B. 0,0 1;5 mm. Valve linear, with gibbous ends. Median line straight. Axial area narrow, on the 

 dorsal side moderately broad, with some few oblique striai at the ends. Dorsal part with about 

 14 striae in 0,oi mm. — A. S. Atl. XXXIX f. 20. 



Marine ? 



This species, which I know only from the A. S. Atl., seems to be very characteristic and 

 requires a more complete examination. 



6. A. Pusio Cl. — Frustule in outline broadly elliptical, with truncate ends. L. (),o2.'i to 

 0,027; B. 0,017 mm. Median line strongly biarcuate. (Jentral nodule large. Axial and central 

 areas not distinct. Dorsal and ventral side with strong stria-, about 14 in 0,oi mm., not inter- 

 rupted and not distinctly punctate. — PI. Ill f. 40. 



Brackish water, marine: Coast of Sweden (Cl. M. D. N:o 157j; Balearic Islands! Hilo, Sand- 

 wich Islands (in almost fresh water). 



