1G2 C.-A. Westerlund, 



Hab. In Suecia cum pifecedente sed rariiis. (In livulo ad Hofiis 

 prope Göteborg primura invenit clar. Malm). 



8. PISIDIUM AEC^FORME Malm. 



Concha parum inaîquilateia, snbrliorabea, antice et postice obtuse au- 

 gulata, ventricosa, tenera, fragilis, tenuiter striata, nitidissima, albido-lute- 

 scens vel, margine excepto, cinerascenti-fulva; umhones proniinuli, validi, 

 uatibus convexiusculis; margo ventralis subrectus; valvidce interne anguluni 

 ad 130" formantes. Long. 3, alt. 2|, cr. 1| mm. 



Pisidiwn arcaforme Malm Götcb. Vet., Vitt. Samh:s Hiiiidl. Ill (18.j5) p. 101. cum 

 ti^. Möreh Syn. Moll. Dan. (1864) p. 7.3. Westerlund Sv. Moll. (1865) p. 128; 

 Coll. Typ. Moll. Su. (1868) n:o 121. 



Pisidiwn roseiun (Scholtz?) JefiVeys Brit. Conch. I (1862) p. 26 (ex specim. orig. ab 

 ipso auctore missis). 



Hab. In Suecia prov. Skåne in aquis stagnantibus ad Lund (C. 

 A. W.) nee non in fluviis Helgeå et Rönneå (J. Lind.^^hl!!); prov. Blekinge 

 ad Ronneby (G. A. W.); prov. Westergötland ad Göteborg in Q villebäcken 

 (Malm); prov. Ne rike ad Adolfsberg prope Örebro (Hartman); prov. 

 Östergötland ad Omberg (C. A. W.) et ad Mjölscfall (E. V. Goes!!). 



9. PISIDIUM NITIDÜM Jen. 



Concha parum inaiquilatera, orbiculato-ovalis, compressiuscula, tenuis, 

 tenuiter striata, ad nates sulculis 2 — 5, inferne sulcis 1 — 2, nitidissima, lu- 

 tescens vel lutescenti-cinerea, margine excepto; umbones subdepressiusculi, 

 natibus convexiusculis; margines omnes regulariter curvati; valvidœ inferne 

 angulum rectum formantes. Long, 3, alt. 2|, cr. 1\ mm. 



Pisidiwn nitidum Jenyns Monogr. Cycl. in Trans. Phil. Soc. Conch. IV (183.3) p. 304. 

 t. 20. f. 7, 8. Malm Göteb. Vet., Vitt. Sarah:s Hanill. II (1851) p. 131; III 

 (1855) p. 110 cum üg. Jeffi-eys Brit. Coneh. I (1862) p. 25. Reeve Brit. Moll. 

 (1863) p. 231. Mörch Syn. Moll. Dan. (1864) p. 74. Westerlund Sv. Moll. 

 (1865) p. 129; Coll. Typ. Moll. Su. (1868) n:o 122. 



Hab. In Suecia sat frequenter ad Quillebäckcn et in Fessbergs å 

 prope Göteborg prov. Westergötland legit celeberr. Malm; in amne Rön- 

 neå prov. Skåne (J. Lindahl!!), ad Mjölsefall prov. Östergötland (E. v. 

 Goes!!) ad Bredvik in Lidingön prope Stockholm (Hartman). — Quœri- 

 tur liœc species bona, sed parum cognita, sajpissime in specim. junioribus 

 P. obtusalis, a quibus tamen longe di versa! 



