Photo of an apertural view of a shell of <i>Balea perversa</i>. Locality: Norway, Telemark, Vråvannet. Scale bar is 1 mm.
P. Glöer
CC BY 3.0
von Proschwitz T. (2010). "Three land-snail species new to the Norwegian fauna: <i>Pupilla pratensis</i> (Clessin, 1871), <i>Vertigo ultimathule</i> von Proschwitz, 2007 and <i>Balea sarsii</i> Philippi, 1847 [= <i>B. heydeni</i> von Maltzan, 1881]". <i>Fauna norvegica</i> <b>30</b>: 13-19. <a rel="nofollow" class="external autonumber" href="http://www.ntnu.no/ojs/index.php/fauna_norvegica/article/view/628">[1]</a>. Figure . Cropped from the figure 6. <a href="https://en.wikipedia.org/wiki/Digital_object_identifier" class="extiw" title="w:Digital object identifier">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.5324%2Ffn.v30i0.628">10.5324/fn.v30i0.628</a>