CRITICAL BIBLIOGRAPHY. Ve 
Of the remaining shells named Unio, Nos. 9 and 10 are now referred to 
Anthracomya (Salter), Nos. 11 to 14 to Carbonicola (M‘Coy), while Nos. 15, 16, 17, 
and 18, described as Modiola, Mytilus, and Avicula, are now referred to Naiadites 
(Dawson). The figures are good and very typical, except in the case of Carbonicola 
robusta and Anthracomya dolobrata, which are from imperfect specimens. 
1842. In 1842 8. Stutchbury (‘ Ann. and Mag. Nat. Hist.,’ vol. viii, p. 481) 
proposed the name Pachyodon for certain Liasic and other shells which possessed a 
peculiar hinge-tooth, but he did not include any Coal-measure shells under this 
denomination ; and it was from external appearance only that later on Captain 
Brown considered that the Coal-measure Unios might belong to this genus. 
1842. In 1842 appeared Agassiz’ translation of Sowerby’s ‘ Mineral Conchology,’ 
in which he proposed the name Cardinia for the shells of the Coal-measures pre- 
viously described as Unios, considering them to be related to certain Jurassic forms. 
About the same year (1842) de Koninck described and figured nine forms in 
his ‘ Des animaux fossiles du bassin Carbonifére de la Belge,’ only one of which 
(Cardinia nana), which Geinitz thinks’ belongs to Hstheria, was mentioned for the 
first time. Iam told by Professor Dewalque, of Liége, that these specimens are in 
the museum of Cambridge, Massachusetts. They are as follows: 
Cardinia acuta. Cardinia nana. 
3 subconstricta. 3 abbreviata. 
PA atrata. 5 tellinaria. 
se robusta. a carbonaria. 
:; phaseolus. is ovalis. 
He follows Agassiz in referring these forms to Cardinia, and describes the 
shell in such a manner that it is evident he never saw an interior of a Coal-measure 
shell, and that he took his type from Jurassic specimens. he figure of Cardinia 
robusta is remarkable, and has apparently been drawn from Sowerby’s type, 
which, however, is incomplete, so that the lines of growth terminate abruptly ; 
but in the Belgian form the lines of growth are carefully curved upwards to end, 
as if naturally, in the posterior slope. 
This form is not mentioned by any Continental author by name, and is only 
figured by Achepol under a different title,” and in that case is found in a different 
coal-field. De Koninck’s figure of Cardinia carbonaria is very different from Unio 
carbonarius, Bronn, to which it is referred. 
1843. Colonel Portlock, in his ‘ Geological Report on Londonderry,’ p. 568, 
mentions a shell described as Unio ? figured pl. xxxvii, fig. 6, as a doubtful shell 
with a deep impression near the beak. It is, however, associated with marine shells, 
' «Neues Jahrbuch f. Min.,’ &c., 1864, p. 654; see also ‘ Report British Association’ (for 1887), 
1888, pp. 68 and 69, where Ludwig’s Permian Cyclas nana (1861) and de Koninck’s Upper 
Carboniferous Cardinia nana (1842), which are distinct forms, are referred to the genus Estheria. 
2 Vide infra. 
3 
