148 UNIONID-A. 
Var. IV. radidta (Colb.). Thinner, with yellow and 
green radiations. 
2. A PICTORUNEN(pancers ) Lz. Pl. 1X, f. 18. 
Oblong, solid, usually narrower than U. temzdus. The “égament 
is parallel with the lower margin, whereas the “gament of the last 
species, if produced, would meet the line of the lower margin and 
form an angle. Its colour is usually a much brighter green, and it is 
more glossy than the last species ; it is also narrower in proportion to 
its size, and is less solid. L.°1°33 ins. B. 3 ins. 
The “ Painters’ Mussel” is found in similar localities to 
U. tumidus, and often approaches it in appearance, so 
much so that there has been great doubt of its being a 
distinct species. Mr. Rogers informs me that specimens 
found in canals near Manchester are lined with a beauti- 
ful salmon-coloured nacre, due perhaps to the refuse at 
the bottom of the canals, and I have taken specimens 
similarly coloured at Castle Ashby ponds, Northants. 
In the same article quoted under the last species, there 
is mention of a specimen the length of which is 2,%, inches 
and the breadth 54 inches; this shell was taken in the 
same pond as the large U. fumidus mentioned above, 
and here again I may mention that from the same spot 
where I took the large /¢wmidus I have specimens of 
pictorum 24 inches in length and 44 in breadth. The 
most beautiful specimens I have seen have come from a 
muddy bottom ;a sandy bottom alters the character in a 
wonderful manner. 
