Notes on Margaritana margaritijera (Linne). 333 



1882 Margaritana margaritijera Esmark, Land and Freshwater 



Mollusca in the Arctic 



Regions of Norway, p. 103. 

 3:884 >> " Clessin, Deutsche Excursions 



Mollusker-Fauna II., AufL, 



P- 529-32. 

 1887 ,, ,, Clessin, Die Moll. - Fauna, 



Oesterreich, Ungarns u. d. 



Schweiz, p. 722. 

 1896 ,, „ L. E. Adams, The Collector's 



Manual of Brit. Land and 



Freshwater Shells, 2 edit., 



p. 149-50. 

 igoo ,, ,, Goldfuss, Die Binnenmollusken 



Mittel-Deutschlands, p. 263- 



65. 



1917 „ „ Schlesch, Notes on Planorbis 



and Margaritana in Iceland 

 (The Naturalist, p. 201). 



Concha ovali-oblonga, compressa, crassa, margine superiore 

 curvato, inferiore recto vel sinuato ; dentibus cardinalibus crassis, 

 conicis, lateralibus nullis. 



L. 120-135, ait - 5 -65, cr. 35-40 mm. 



This interesting mussel was named ' Musculus niger, om- 

 nium longe crassimus ; concha longce ; species Gesn. Aldrov.' 

 by Martin Lister. Margaritana margaritijera is one of the few 

 species that have a wide distribution. According to Lionel 

 Adams the ' pearl mussel ' is found in rivers in mountainous 

 districts in several parts of Great Britain from Shetland to 

 Cornwall, but only to the west of a line drawn from Scarborough 

 to Exeter, and also in Ireland and the Isle of Man. On the 

 Continent it is distributed from Aragon, in Northern Spain, 

 the Pyrenees, France, the Vosges, the Ardennes, Belgium, 

 Netherlands, in a few places, Germany*, Bohemia, Russia 

 (Dniester, Don and Volga to the White Sea), Denmark (in 

 Vardeaa, Jutland), the Scandinavian peninsula from Scania to 

 the Arctic Ocean, f In Finland it is common and distributed 

 in the numerous lakes and streams. It has been recorded for 

 Iceland, a single specimen being found in 1863, near Reyk- 

 javik. Further, Margaritana margaritijera lives in Siberia, 

 Altai Mountains, Manchuria and the eastern and western river 

 systems of North America. 



* Bavaria, Bohmerwald, Fichtelgebirge, Saxony, several brooks in 

 Silesia, Hanover, Thuringia, in the Sauer in Nassau, Westerwaldes and 

 Hundsriickens. 



•f Miss Birgithe Esmark records M. margaritijera from Senjen Island 

 and Borge in Lofoten Islands ; also in Berlevaag in East Finmarken and 

 in South Varanger. 



1917 Oct. 1. 



