KONGL. SV. VET. AKAT)EM1ENS HANDLIN6AK. BAN7) 27. N:o 3. 87 



like terminal fissures. Area very broad, linear, slightlv widened in the middle. Striae 8 in 0,oi 

 mm. — A. S. Atl. XLIII f. 20. 



Fresh water: Celebes (Atl.). 



46. P. Integra G-run. Ms. — V. linear, with parallel margins, or slightly gibbous in the 

 middle. Ends cuneate, often subcapitate. L. 0,n 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. Striae 7 in 0,oi 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 each side by a silicious rib. 



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

 rostrate ends. L. 0,055 to 0,075; B. 0,oo9 to 0,012 mm. Median line filiform, with approximate 

 median pores and semicircular terminal fissures. Axial area wider than a third of the breadth of the 

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



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

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

 Grun. Verb. 1860 p. 521, PI. IV f. 21. N. (Finn.) nodosa Greg. M. J. 1856 PI. 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 capitata. — Ends capitate. Area often punctate. Striae 10 to 11 in 0,oi mm., con- 

 vergent at the ends. — Finnularia isocephala Ehb. M. G. V: 3 f. 21? P. monile Ehb. M. G-. 

 XVII: 1 f. 12? 



Fresh water: Sweden (Lake Rosslangen in Kalmar Ian)! America (Houghton, Michigan)! 



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

 ends. L. 0,o8 to 0,o9; B. 0,oi4 mm. Striae 9 in 01 mm., interrupted in the middle, convergent 

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

 N. Sc. Philad. 1861 p. 67 PI. II f. 7. Nav. peripunctata Brun. D. Esp. n. p. 37 PI. 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,oo7 to 0,oi3 mm. Median line filiform with 

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

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

 rupted. — Stauroptera parva Ehb. Am. Ill: 1, f. 19? P. parva Greg. M. J. II PL IV f. 11. Nav. 

 parviila Rales Pritch. Inf. p. 908 (1861). Grun. Foss. D. Ost. Ung. p. 143 PL XXX f. 37. Nav. 

 gibba var. brevistriata V. H. Syn. p. 78 PL VI f. 5. A. S. Atl. XLIII f. 21. Nav. gibba forma, curta 

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

 curtestriata Pant. Ill PL XII f. 188 (1893). Nav. (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. Lagerstedtii Cl. — L. 0,025 to 0,033; B. 0,oo5 to 0,oo8 ram. Striae 8,5 to 10 in 0,oi 

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



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



Var. Novce Zealandice Cl. — L 0,0.32; B. 0,oo8 mm. Striae 12 in 0,oi mm. interrupted on 

 both sides of the central nodule. 



Fresh water: New Zealand (Rotomahana)! 



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

 mm. Median line with approximate central pores. Area broad, lanceolate. Striae 21 to 22 in 



