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



As Cymbella elegans Cramer has issued in Rabh. Alg. Eur. N:o 1441 (1863) a sample con- 

 taining several Cymbellee, as C. Cistula, C. helretira, C. deUcatula, C. leevis, C. affinis, C. lepto- 

 ceras, C. amphicephala and C. aspera. As no description or figure of C. elegans is given, it is 

 impossible to determine what form the name denotes. 



9. C. laevis Naegbli (1849). — V. strongly asymmetrical, semilanceolate, gradually tapering 

 from the middle to the ends. Dorsal margin arcuate; ventral margin straight or slightly convex 

 in the middle. L. 0,o25 to 0,o35; B. 0,oo7 to 0,oo8 mm. Median line somewhat excentric and 

 slightly arcuate. Axial area indistinct. Striae of the dorsal side 13 (middle) to 15 (ends) in 0,oi 

 mm., slightly radiate. Strife of the ventral side 16 (middle) to 17 Cends) in 0,oi mm. almost pa- 

 rallel and finely punctate. — Naeq. in Kiltz. Sp. Alg. p. 59. V. H. Syn. p. 62 PI. Ill f. 7. 

 A. S. Atl. IX f. 35. 



Fresh] water: Norway (Dovre)! Sweden (Gellivaara to Ortofta in Skane)! Finland (Lapland 

 to Karelen)! Scotland! Zurich (Grun.), Tours du Rhone! 



10. 0. pusilla GrRUN. (1875). — V. asymmetrical, narrow, semilanceolate, with subacute ends 

 and arcuate dorsal, straight or slightly convex ventral, margin. L. 0,23 to 0,04; B. 0,oo5 to 0,oo7s 

 mm. Median line straight, strongly excentric. Axial area very narrow, not, or slightly, dilated 

 around the central nodule. Strise 15 to 18 (middle) or 16 to 20' (ends) in 0,oi mm., radiate in 

 the middle, transverse at the ends. — Grun. in A. S. Atl. IX f. 36, 37. V. H. Syn. PL III f. 5. 



Brackish water: Sweden (Baltic: Gothland, MalmO)! Halle! Neusiedler See (Grun.), Caspian 

 Sea (Grun.), Normandy! Belgiiim (V. H.), Bayonne (Atl.), Sardinia (Grun.), Mouth of Jenissey! 

 South Africa! Ecuador! 



11. C. yarrensis A. S. (1881). — V. narrow, semilanceolate, acute. L. 0,o75 to 0,ii; B. 

 0,0 12 to 0,015 mm. Median line nearly central; its terminal fissures in the ends. Axial area 

 narrow, linear, dilated in the middle to an elongated central area. Strise 11 in0,oi mm., somewhat 

 more distant in the middle, where they are radiate, parallel in the ends. — Encyon? yarrense 

 A. S. Atl. LXXI f. 16. 



Sliglitly brackish water: Yarra-Yarra (Australia)! Tasmania! 



12. C. ruplcola Grun. (1881). — V. slightly asymmetrical, lanceolate, gradually tapering 

 from the middle to the subacute ends. L. 0,027 to 0,034; B. 0,oo45 to 0,oo55 mm. Median line 

 almost central, straight. Axial area narrow, not dilated in the middle. Dorsal strife 12 (middle) 

 to 15 (ends) in 0,oi mm. slightly radiate. Ventral strise 16 in 0,oi mm. slightly radiate — 

 Grun. in A. S. Atl. LXXI f. 70, 71. 



Fresh water (moist rocks): Arctic America! Scotland (V. H. Types), Salzburg (Atl.). 

 This species is very nearly akin to C. Imvis and differs scarcely in anything except the 

 less asymmetrical valves. 



13. C. Beinhardtii Grun. (1875). — V. slightly asymmetrical, elliptic-lanceolate, with 

 convex dorsal and ventral margins. Ends obtuse. L. 0,03 to 0,06; B. 0,oo8 to 0,oi4 mm. Median 

 line nearly central, straight. Axial area narrow, gradually dilated to the middle, where it ex- 

 pands to a moderately large central area. Strise 10 (middle) to 13 or 14 (ends) in 0,oi mm. The 

 median strits are more distant than the rest and slightly radiate. Towards the ends the striae 

 become almost parallel. — A. S. Atl. IX f. 27. Cl. M. D. N:o 132, 



Fresh water: Norway (Romsdalen)! Steinitz Sea (Atl.). 



The above description is from specimens in Cl. M. D. 132, determined by Grunow as 

 C. Eeinhardtii. 



14. C. leptoceros (Ehb. 1843?) Grun. — V. asymmetrical, lanceolate, with slightly gibbous 

 ventral margin and obtuse, sometimes slightly attenuated ends. L. 0,o2 to 0,04; B. 0,oo8 to O.oi 

 mm. Median line slightly arcuate. Axial area linear, not dilated around the central nodule. 



