114 UNIO LANDANENSIS. 



wise ; left valve with a very indistinct tooth and two late- 

 ral ones ; anterior muscular scars shallow , posterior ones 

 and pallial scar scarcely visible. 



Length 41, breadth under the beaks 19, behind the li- 

 gament 22 mill. Diam. 18 mill. 



Hob. Landana (Congo), collected by Mr. Petit Ainé 

 (Leyden Museum). 



This shell has externally much the appearance of being 

 an Anodonta, the very weak hinge increases still the re- 

 semblance. Prom Unio Juliana Rang , which should also 

 look like an Anodonta , it differs , as far as may be j udged 

 from the description , by the form , which in Juliana is 

 described as »oblongue ou arrondie, concave", by the epi- 

 dermis which is yellow , often adorned with a large num- 

 ber of green rays in U. Juliana^ while the nacre in that 

 shell is not rosy. About the sculpture of the beaks of U. 

 Juliana, Rang says: »leurs soramets a l'extérieur sont ar- 

 mes, surtout dans le jeune age, de petits tubercules spi- 

 uiformes." 



Rhoon near Rotterdam, March 1891. 



JS^otes from the X^eyden iMuseuixi, Vol. X.1II. 



