PLATE III.— (Bivalves). 



Fig. Species d- Authority Colouring Chief Charaeteristics Habitat 



42 Pisidium fontinale 



(Drapaniaud) 



43 — amnicum (Miill.) 



44 — milium (Held) 



45 — pusillum (Gmel.) 



46 — nitidum (Jenyiis) 



47 Sph^rium corneum 



(Limie) 



48 — lacustre (Mull.) 



49 — rivicola (Leach) 



50 — pallidum (Gray) 



Grey 



Greyish or yel- 

 lowish 



Grey 



Greyish or yel- 

 lowish 



Grey 



Yellowish horn- 

 colour 



Gi-ey 



51 Unio pictorum 



(Linne) 



52 — tumidus 



(Philippsson) 



53 — marg-aritifer 



(Liiuie) 



54 Anodonta cygnea 



(Liune) 



55 — anatina (Linne) 



Keddish or olive- 

 brown 



Greyish or yel- 

 lowish 



Yellowish green 

 Dark brown 

 Dull black 



Yellowish green 

 or brown 



Prominent beaks, tri- 

 angular shape 



Large size, ridges, 

 triangular shape 



Prominent beaks, 

 oblong shape 



Beaks nearly central, 

 oval shape 



Glossiness, beaks 

 central, round shape 



Glol)ular form, oval 

 shape 



Capped beaks, sharp 

 edges, squarish shape 



Large size, colour 



Oblong shape, sharp 

 shoulders 



Narrow oblong shape 



Oval shajie, weight, 

 ami solidity 



Ditches, ponds, 



etc. 



Ditto 



Ditto 



Ditto 



Ditto 



Ditto 



Ditto 



Canals and slow^ 

 rivers 



Canals and ponds 

 Canals, lakes, etc. 

 Ditto 



Colour, eroded beaks Rivers 



Large size, parallel Canals, lakes, etc. 

 upper and lower 

 margins 



Ditto 



Raised hinge-line 

 forming angle with 

 lower margin 



Ditto 



56 Dreissensia poly- Yellowish, zig-zag 

 morpha (Pallas) markings 



Boat shape, marking, Canals, rivers, 

 byssus attachment lakes 



Frequency 

 Common 



Frequent 



Frequent 



Common 



Local 



Common 



Frequent 



Frequent 



Local 



Conrmon 



Common 



Local 



Common 



Common 



Common 



