KONGL. SV. VET. AKADEMIKNS HANDLINGAR. BAND 27. N:o 3. 76 



II. Capitatse. 

 Artificial keif. 



J I ValvK rostrate P. iiiicrostaiiroH Ehb. 



I — capitate 2. 



,, I Valve with undulated margins p. mesolcpta Ehb. 



"" ) — not undulated 3. 



I Valve linear P. interriipta W. Sm. 



\ — lanceolate 4. 



( Capitate ends broad and large P. globiceps Greg. 



. I Va 



ends small f). 



Valve lanceolate P. Braunii Gkun. 



almost linear (5. 



. I Stria 1(5 to 18 in 0,oi mm P. apiyendiculat.a Ac. 



1 — 12 to 13 in 0,01 mm P. subcapitata Greg. 



6. P. appendiculata Ag. (1828). — V. linear, gently tapering from the middle to the 

 slightly rostrate-capitate ends. L. 0,oi8 to 0,o36; B. (),oo4 to <),oor) mm. Area very narrow, dila- 

 ted in the middle to a transverse fascia. Strife 16 to 18 in 0,oi mm., slightly radiate in the middle, 

 convergent at the ends. — Frustidia app. Ag. Icon. Alg. Enr. PI. I (according to Kiitz). Nav. 

 app. KiJTz Bac. p. 93 PI. Ill f. 28. V. H. Syn. p. 79 PI. VI f. 18, 20. N. app. v. irrorafa Grun. 

 V. H. Syn. PL VI f. 30, 31. Nav. Naveana Grun. Verh. 1863 p. 149 PI. IV f. 24. V. H. Syn. 

 PI. VI f. 29. 



Fresh water (moist rocks, mosses etc.): Iceland! Scotland! Sweden (Gothland)! Belgium 

 (V. H.), Brunn (Gru.n.), Bengal! Australia (Blue Mountains)! Greenland! New Jersey (Hoboken)! 

 Ecuador! 



Var. hudcnsis Grun. (1880). — V. gibbous in the middle, with distinctly capitate ends. 

 StrifE 20 to 23 in 0,oi mm. — V. H. Syn. PL VI f. 27, 28. 



Hot springs: Buda-Pesth (Grun.), New Zealand! 



P. appendiculata is closely connected with P. subcapitata and P. molaris and the other hand 

 through the var. budensis with P. Braunii. 



7. P. Braunii Grun. (1876). — V. lanceolate, with capitate or subcapitate ends. L. 0,o.3.t 

 to 0,05; B. 0,009 to 0,008 mm. Axial area narrow, gradually increasing in breadth towards the 

 middle of the valve, where it expands to a large and bioad, transverse fascia. Stria? 11 to 12 in 

 0,0 1 mm., divergent in the middle, convergent at the ends. — Nav. Brauniana Grun. in A. S. Atl. 

 XLV f. 77, 78. Nav. Braunii Grun. in V. H. Syn. p. 79 PL VI f. 21. 



Fresh water: Iceland! Sweden (Rcsslangen in Kalmar Ian! Loka, Atl.), Finland! Belgium 

 (V. H.), Bengal! Australia (Blue Mountains)! Argentina! Brazil! 



8. P. subcapitata Greg. (1856). — V. linear, with subcapitate to capitate ends. L. 0,o3 to 

 0,o!i; B. 0,005 to 0,006 mm. Axial area narrow or indistinct. Central area a transverse fascia. 

 Strise 12 to 13, slightly divergent in the middle, convergent at the ends. — M. J. IV p. 9 PL I 

 f. 30. Fin. Hilseana Janisch in Rabh. Alg. Sachs. N:o 953 (1860). Nav. Hilseana A. S. Atl. XLV 

 f. 65. V. H. Syn. p. 77 Suppl. A. f. 11. Nav. subcapitata A. S. Atl. XLIV f. 53, 55. V. H. Syn. 

 p. 78 PL VI f. 22. A. S. Atl. XLV f. 59, 60. 



Fresh water: Spitsbergen! Sweden (Helsingland, Upsala, Marstrand, Gothland)! Finland! 

 Scotland! England! Kiel! Belgium (V. H.), Bengal! Amsterdam Island! Australia (Blue Mountains)! 

 Argentina! Ecuador! Greenland! 



Var. paticistriata Grun. — Strise short, gradually shortened towards the middle, where is 

 a very broad transverse fascia. — V. H. Syn. p. 79 PL VI f. 23. 



