CRITICAL BIBLIOGRAPHY. 



19 



Anthracomya Williamsoni ; but I have no doubt at all as to the genus, as there are 

 portions showing casts of the hinge-line and posterior end. 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. xii, 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 : 



Pachyodor 



, Gerardii. 



>? 



lateralis. 



>) 



sulcatus. 



»» 



rugosus. 



») 



subrotundus. 



., 



bipennis. 



>» 



Dawsoni. 



>> 



nanus. 



,, 



Rhindii. 



ty 



amygdalus. 



»J 



exoletus. 



»» 



dubius. 



M 



subtriangularis 



Pachyodon 



Smithii. 



» 



Embletoni. 



>> 



Hey ii. 



»> 



agrestis. 



»> 



similis. 



>> 



turqidus. 



>) 



nucleus. 



!) 



Blaydsii. 



>> 



Aldamii. 



)) 



antiquus. 



)> 



transversus. 



>> 



Levidensis. 



» 



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 wC Anthracosia for a 

 group of Unionidae 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 1 save the sentence quoted. 



1844. In the same year and volume, p. 100, is an interesting and valuable 

 paper by Mr. H. E. Strickland on the genus Gardinia. He points out that in 

 ' Etudes critiques sur les Mollusques fossiles,' Agassiz, the author of the term, 

 seems to regard Gardinia as exclusively confined to the Lias and Lower Oolite, 

 and justly criticises de Koninck for classifying " these Coal-measure shells as 

 Gardinia, 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. 



