KONGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 27. N:0 3. 87 



like terminal fis.sures. Area very broad, linear, slightly widened in the middle. Strise 8 in 0,oi 

 mm. - A. S. Atl. XLIII f. 20. 



Fresh water: Celebes (Atl.). 



46. P. integra Grun. Ms. — V. linear, with parallel margins, or slightly gibbous in the 

 middle. Ends cvineate, often subcapitate. L. O, ii to 0,12; B. 0,oi6 to 0,oi7 mm. Median line 

 flexuose, with approximate central pores and small, semicircular, terminal fissures. Area broad, 

 linear, gently dilated in the middle. Striee 7 in 0, 01 mm., almost parallel, not interrupted. — 

 A. S. Atl. XLIII f. ly. 



Fresh water: America (Crane Pond, Waltham Mass.)! French Pond (Atl.). 

 The median line is bordered on eaeh side by a silicious rib. 



47. P. nodosa Ehb. (1838). — V. more or less distinctly triundulate, with capitate to 

 rostrate ends. L. 0, 0.55 to 0,075; B. 0,00» to 0,oi2 mm. Median line filiform, with approximate 

 median pores and semicirciilar terminal fissnres. Axial area wider than a third of the breadth of the 

 valve. Strise 8 to 10 in 0, 01 mm. parallel, more or less convergent at the ends, interrupted or not. 



Forma genuina. — Ends rostrate. Strise 8 to 9 in 0,oi mm. parallel throughout, uni- or 

 bilaterally interrupted. — Nav. nodosa Ehb. Inf. p. 179 Pl. XIII f. 9? M. G. XVII: 2 f. 12, 13. 

 Grun. Verh. 1860 p. 521, Pl. IV f. 21. N. {Finn) nodosa Greg. M. J. 1856 Pl. 1 f. 5. A. S. 

 Atl. XLV f. 56 to 58. 



Fresh water: Scotland (Greg.)! France (Lac Gerardmer, Vosges)! America (Canada, French 

 Pond, Albany)! 



Forma capifata. — Ends capitate. Area often punctate. Strise 10 to 11 in 0, 01 mm., con- 

 vergent at the ends. — Pinnularia isocepliala Ehb. M. G. V: 3 f. 21? P. monile Ehb. M. G. 

 XVII: 1 f. 12? 



Fresh water: Sweden (Lake Rosslängen in Kalmar län)! America (Houghton, Michigan)! 



Var. FormÅca Ehb. (1843). — V. triundulate, with strongly inflated middle and capitate 

 ends. L. O, os to 0,09; B. 0,014 mm. Strife 9 in O 01 mm., interrupted in the middle, convergent 

 at the ends. — Nav. Formica Ehb. Am. p. 130. M. G. IV: 3 f. 8. Pinnul. polyonca Lewis Proc. Ac. 

 N. Se. Philad. 1861 p. 67 Pl. II f. 7. Nav. peripunctata Brun. D. Esp. n. p. 37 Pl. XVI f. 11, 1891. 



Fresh water: N. America (Waltham, Mass.! N. Jersey to Savannah, Lewis). 



48. P. parva (Ehb. 1843?) Greg. (1854). — V. linear, gradually tapering from the middle 

 to the obtuse or capitate ends. L. 0,04 to 0,07; B. 0, 007 to 0,oi3 mm. Median line filiform with 

 approximate central pores and semicircular terminal fissures. Axial area broad, lanceolate. Strise 

 9 to 10 in 0,01 mm., almost parallel, convergent at the ends, frequently uni- or bilaterally inter- 

 rupted. — Stauroptera parva Ehb. Am. III: 1, f. 19? P. ^larva Greg. M. J. II Pl. IV f. 11. Nav. 

 parviila Rälfs Pritch. Inf. p. 908 (1861). Grun. Foss. D. Öst. Ung. p. 143 Pl. XXX f. 37. Nav. 

 gibha var. hrevistriata V. H. Syn. p. 78 Pl. VI f. 5. A. S. Atl. XLIII f. 21. Nav. gihha forma, curfa 

 Bleisch Rabh. Alg. Sachsens N:o 951 (1860). Nav. higlohosa Schum. P. D. II Nacht. f. 48? Nav- 

 curtestriata Pant. III Pl. XII f. 188 (1893). Nar. (peregrina var.?) curtestr. Pant. II p. 44 Pl. II 

 f. 19 (1889). 



Fresh water: Sweden! Finland! Scotland (Greg.), Holstein! Dresden! Hungary, foss. Grun., 

 Java! Australian Alps! New Zealand! North America (Crane Pond, Illinois)! Argentina! 



Var. Lagerstedtn Cl. — L. 0,025 to 0,033; B. 0,on5 to 0,oo8 mm. Strite 8,5 to 10 in 0, 01 

 mm. — Nav. parvula Lagst. Spitsb. D. p. 26 Pl. II f. 4 1873. 



Fresh water: Beeren Eiland, Spitsbergen (Lagst.). 



Var. Novce Zealandice Cl. — L 0,032; B. 0,oo8 mm. Strise 12 in 0, 01 mm. interrupted on 

 both sides of the central nodule. 



Fresh water: New Zealand (Rotomahana)! 



49. P. modesta Grdn. (1882). - V. linear-lanceolate with obtuse ends. L. 0,035; B. 0,oo7 

 mm. Median iine with approximate central pores. Area broad, lanceolate. Strise 21 to 22 in 



