32 CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 



The notes of interrogation and remarks are my own, from a personal examination 

 of the specimens figured. 



One new form, " Anthracomya Wardi" is described by R. Etheridge, sen., as if 

 that genus belonged to the Myacidse. In the text which deals with the strati- 

 graphy of the coal-field, the beds in which the various forms occur are carefully 

 noted. 



1878. Mr. G. H. Kinahan, M.R.I.A., gives in his 'Geology of Ireland' a 

 plate (pi. iv) with two forms of Coal-measure bivalves from Bilboa, Queen's Co., 

 which he names Myacites fabseformis and Anthracosia Bilboensis. I have seen 

 examples of the latter in the Royal Museum, Dresden, which were collected from 

 Bilboa by Dr. Geinitz, and which I recognise as Anthracomya Williamsoni (Brown). 1 



He quotes Mr. Baily as to the occurrence of bivalve mollusca in the various 

 Irish coal-fields. 



1880. In 1880 Dr. John Young read, January 13th, a paper, subsequently pub- 

 lished in the ' Transactions of the Geological Society of Glasgow,' vol. vi, p. 223, 

 for that year, entitled " Notes on some Carboniferous Lamellibranchs." He dis- 

 cusses and sums up in favour of the fresh-water habitat of the genera Anthracoptera, 

 Anthracomya, and Anthracosia. He there chronicles his discovery of prismatic 

 cellular structure in the shells of Anthracoptera {Naiadites) . 



1880. In the ' Palseontographica,' vol. xxvii, p. 109, is a paper by Dr. Hans 

 Polig, under the curious title " Maritime Unionen." In this he advances the view 

 that the Anthracosise of the Coal-measures, the Unios of the Triassic, and the 

 Gardinise of the Jurassic form a natural group, connecting on the one hand the 

 Cyprinidss, and on the other Najades. 



1880-83. ' The Niederrheinisch Westfallisch Steinkohlen-Gebirge Atlas ' was 

 published by Achepol during the years 1880 to 1883. This remarkable work is 

 distinguished by having, instead of plates, photographs of the objects themselves. 

 These photographs are often so imperfect, from bad arrangement of the light during 

 the process of photography, and the objects themselves are so often fragmentary 

 and indistinct, that little or nothing can be made out of them. Added to this, the 

 inventive genius of the author as to species-making is excessive, and he describes and 

 figures thirty-seven forms, thirty-two of which are said to be new, although he has 

 adopted names which previous authors had given to different forms. 



Anthracosia Ooldfussi, Achepol. Anthracomya Williamsoni. 



„ tellinaria. 



„ securiformis, Ludwig. 



1 Since going to press I have by the courtesy of the Officers of the Geological Survey of Ireland 

 been permitted to examine the specimens in the Dublin Museum. I consider that the forms labelled 

 there as above are both of them Anthracomya closely allied to A. Williamsoni. 



