166 P. T. CLEVE, SYNOPSIS OF THE NAVICULOID DIATOMS. 



27. C. naviculiforinis Auersw. (1861). — V. elliptic-lanceolate, slightly asymmetrical, with 

 rostrate-capitate eiids. L. 0,o;3 to 0,1147; B. 0, 01 to 0,oi6 mm. Median line almost central, nearly 

 straight. Axial area narrow, linear, suddenly dilated in tlie middle to an orbicular .space. Strite 

 in the dorsal side 14 (middle) to 18 (ends) in 0, 01 mm., on the ventral side 1-1 in D.ni mm. 

 — AiTERSW. Rabh. Alg. E. N:o 10(i5. V. H. Syn. Pl. II f. 5. 6'. rusjndcda W. Sm. B. 1). I Pl. II 

 f. 22 a'. C. ancjlica Lägst. Spitsb. D. p. 42 Pl. II f. 18 (1873). A. S. Atl. IX f. 63. V. H. Syn. 

 Pl. II f. 5. 



Fresh water: Grreenland! Spitsbergen! Beeren Eilaiul (Lägst.), Norway (Romsdalen. Do^re)! 

 Sweden! Finland! Holstein! Harz (Atl.), Jenissey! Nevv-ZealandI Australia! 



Heiberg (Consp. Crit. p. 108) remarks tliat Cynih. cuspidnta W. Sm. is not the species of 

 KlJTZiNG, bnt possibly C. navicuUformis, of whicb he gives several figiires (Pl. 1 f. 3), which 

 liowever are much more similar to C. anipliicephala than to this species. Lagerstedt projjosed the 

 name C. anglica, believing it to be identical with the species of W. Smith, which is too indistinetly 

 hgured for identification. G. ii.aviculiformis closely resembles C. avipliktphala, from which it is 

 distinguished by the larger central area. 



28. €. hybrida Grun. (1878). — V. linear, almost symmetrical, with rostrate ends. L. 

 0,045; B. 0,009 mm. Median line almost central and straight. Axial area narrow; central area 

 large, subquadrate. Striaj 11 in 0, 01 mm. almost parallel, tinely punctate. — Grlx. in Cl. M. D. 

 N:o 161. Icon. nostr. Pl. IV f. 23. 



Fresh or very slightly brackish water: Sweden (Gothland, Lefra.sjön in Skåne)! 



29. C. spuria Cl. N. Sp. — V. asymmetrical, lanceolate, with subrostrate ends. L. 0,o5 

 to 0,06; B. 0,013 mm. Median line very slightly ai'cuate, almost central, Axial area narrow, 

 gradually dilated towards the middle. Striee 12 (dorsal, median) to 13 (ventral and dorsal, termi- 

 nal) in 0,01 mm., slightly radiate in the middle, almost parallel in the ends, tinely but distinctly 

 punctate. 



Fresh water: Talbot (Victoria, Australia)! Pichinicha (alpine region of Ecuador)! 



30. C. CHspidata Kutz. (1844). — V. broadly linear-lanceolate, slightly a.symmetrical. with 

 rostrate-capitate ends. L. 0,u4 to 0,095; B. 0, 014 to 0,024 mm. Median line slightly excentric, 

 straight. Axial area narrow, linear; central area rather large, orbicular. Strire 9 or 10 (middle) 

 to 12 or 14 (ends) in 0,oi mm. radiate, iinely lineate. — Kutz. Bac. Pl. III f 40. Heib. Consp. 

 p. 109 Pl. I f. 4. A. S. Atl. IX f. 50 (typical) 53 to 55. V. H. Syn. p. (il Pl. Il f. 3. 



Fresh water: Sweden (Lappland to Upsala and Westergötland)! Norway (Finmark, l)cj\re)! 

 Finland! Paris! Belgiuni (V. H.), England! Germany! Italy! Greenland! Canada! Massachusetts! 

 Jenissey! Kamtschatka! Japan! New Zealand! 



Var. obtusiunculu Grun. (in V. H. Types N:o 19). -- L. 0,o6 to O,o8; B. 0,oi9 to 0,oj mm. 

 Ends more rounded. 



Fresh water: England (V. H. T.). 



31. C. hetoropleiira Ehb. (1843). — V. slightly a.^ymmetrical, lanceolate, with rostrate 

 and truncate to subrostrate, obtuse ends. L. 0, 12 to 0,15; B. 0,033 to 0, 04 mm. ^ledian line 

 almost central, straight. Axial area distinct, linear. Central area large, slightly transversely 

 dilated. Strise 9 to 10 in 0,01 mm. slightly radiate throughout, punctate; puncta 9 to 13 in 0, 01 

 mm. — Finnularia heteropleura Ehb. Am. p. 133. M. G. V: 2 f. 11. Cijnih. Iwf. Kutz. Bac. p. 79. 

 A. S. Atl. IX f. 4, 5. 



Fresh water (arctic and northern regions): Greenland! Norway (Dovre)! Sweden (Lappland)! 

 Russian Lappland! 



