CRITICAL BIBLIOGRAPHY. 1) 
Anthracomya Williamsoni ; but I have no doubt at all as to the genus, as there are 
portions showing casts of the hinge-line and posteriorend. The peculiar wrinkling 
of the periostracum, so frequently seen in Anthracomya, is well shown in one 
specimen on the slab. 
1843. In the ‘ Annals and Magazine of Natural History,’ vol. xi, p. 390, 1843, 
Captain T. Brown figured and described under Stutchbury’s name Pachyodon, as 
new, twenty-six forms from English and Scotch Coal-measures : 
Pachyodon Gerardit. Pachyodon Smithii. 

ss lateralis. 5 Embletoni. 
PA sulcatus. ib Heyii. 
oe TUgosus. a agrestis. 
+9 subrotundus. 3 similis. 
$ bipennis. nS turgidus. 
ss Dawsoni. 3 nucleus. 
as nanus. 5 Blaydsiz. 
5 Rhindiz. 7, Aldamii. 
y amygdalus. A antiquus. 
9 exoletus. | ny transversus. 
6 dubius. 3 Levidensis. 
5 subtriangularis. 3 pyramidatus. 
Of these, I think P. Gerardii and P. pyramidatus may have belonged to 
Schizodus ; and, owing to the fact that Captain Brown did not recognise the 
extent of variation of which this form of genus was capable of assuming, many 
of these names must be considered as synonymous; but, nevertheless, several 
well-marked species and varietal forms are in this paper figured and described for 
the first time : unfortunately the descriptions are meagre, and the original speci- 
mens cannot be traced. 
1844. It was in 1844 that W. King proposed the name “ Anthracosia for a 
group of Unionide characteristic of the Coal-measures” (‘ Annals and Mag. Nat. 
Hist.,’ ser. 1, vol. xiv, p. 313, 1844), which he says he intended to describe in his 
‘Monograph of the Permian Fossils ;’ but nothing further is said by King on the 
subject’ save the sentence quoted. 
1844. In the same year and volume, p. 100, is an interesting and valuable 
paper by Mr. H. H. Strickland on the genus Cardinia. He points out that in 
‘Etudes critiques sur les Mollusques fossiles,’ Agassiz, the author of the term, 
seems to regard Cardinia as exclusively confined to the Lias and Lower Oolite, 
and justly criticises de Koninck for classifying ‘‘ these Coal-measure shells as 
Cardinia, and prefixing a definition of the genus, which seems to be chiefly copied 
from de Christol’s definition of Sinemuria ; and we may, therefore, conclude that 
de Koninck had not been able to examine the interior of the fossils which he 
1 Until 1856, in the ‘ Ann. Mag. Nat. Hist.,’ vide infra. 
