ANTHRACOMYA MINIMA. 117 
Distribution.—Knowles Ironstone, Longton railway-cutting, south of Kidsgrove, 
in North Staffordshire. Middle Coal-measures. Prestolee, near Manchester. 
Black Band, Blaina, South Wales. Wylam Colliery, Northumberland. Scotland : 
Possil; Langton Burn, Dunse; Blackadder Water, Dunse. 
Observations.—When I gave the name A. minima to this shell in 1893 I was 
unaware that the species had been named or described before. By a lucky 
coincidence I was fortunate enough to hit on the same specific name as that given 
by the earliest observer, R. Ludwig. It was the examination of his type 
specimens at Dresden which convinced me of the identity of his shells, though 
they were crushed, with the British forms. Unfortunately, too, his figures are not 
good. At that time Professor Geinitz showed me some specimens labelled Modiola 
Carlotta, Romer, which I could not distinguish from Anthracomya minima. 
I have therefore placed Rémer’s name as a synonym. Rémer thought his’ shell 
had been previously described by Volpersdorf, who however, only gave it the 
generic name of Modiola. 
Salter figures some small shells from the South Wales Coal-field, of whose 
generic affinity he evidently did not feel quite sure, as he calls them Modiola or 
Anthracomya. Judging from figures only, I think it probable that two of his 
specimens (figs. 1 and 2, not 3) may be referred to A. minima. 
The general form of A. minima closely resembles that of A. Phillipsii, but it is 
much smaller; and owing to the fact that the latter shell nearly always occurs 
crushed, it is next to impossible to make out accurately many of its characters. 
The two forms were very gregarious in habit, and are found in large numbers in 
certain beds, but as far as I know not together; other species and genera are 
conspicuously absent, with the possible exception to be noted below. Still there 
is nothing antagonistic to the view that one was only a dwarfed form of the other. 
There often occurs both in Staffordshire and Lancashire, in a bed with 
A. minima, a form to which I gave the name Anthracomya carinata, and it would 
appear on comparing it with a typical specimen of the former to be quite distinct ; 
but a series of intermediate forms occur which completely connect the two. I 
have, therefore, now placed A. carinata as a variety of A. minima. There is a 
resemblance also between our shell and the forms called on the Continent Unio 
carbonarius, Bronn, and Unio Goldfussianus, de Koninck. It is very difficult to 
form any conclusions as to what shells are represented by these names, owing to 
the disappearance of all the types, and the inaccuracy of authors, to which 
Professor Geinitz drew attention in a paper in ‘Neues Jahrbuch’ for 1864, 
p. 651. In the ‘ Petrefacta Germanica,’ p. 181, pl. cxxxi, fig. 20, Goldfuss 
gives a figure of Unio uniformis, Sowerby, which, as de Koninck pointed 
out in his remarks on Cardinia ovalis in his ‘ Animaux fossiles du_ bassin 
Carbonifére de la Belge,’ p. 74, is totally distinct from Sowerby’s shell, and he 
