24 



CARBONICOLA, ANTHRACOMYA, AND NAIADITES. 



Unio Zottneri. 

 „ crassidens. 

 „ batilliformis. 

 „ Geinitzi. 

 „ atratus, Goldf'uss. 



Unio angulatus, Ryckholt. 

 Cyclas elegans. 

 Dreissina Feldmanni. 



,, dilafata. 



,, inflata. 



In 1861 (' Paleeontographica,' vol. x, pp. 21 and 22), in his memoir on the 

 fresh-water shells of the (Permian ?) Coal-formation of the Ural, Ludwig figures 

 and describes Anodonta {Anthracomya ?) TJrallca and A. ? obstipa. 



In 1863, in another paper entitled " Die Palaontologie des Urals " (' Palasonto- 

 graphica,' Band x, p. 18, &c.), he mentions — 



Unio tellinarius, Groldf. 

 „ Ooldfussianus, Koninck. 

 „ Thuringensis, Ludwig. 

 Anodonta carbonaria, Koninck. 

 ,, ovalis, Martin. 

 ,, angulata, Rhyckholt. 

 „ subparallela, Keyserling. 



Anodonta Eichwaldiana, Murchison, Keyserling, 



and Verneuil. 



,, tenera, Eichwald. 



„ Uralica, Ludwig. 



,, obstipa, Ludwig. 

 Cyclas obuncula, Ludwig. 

 Unio lepidus, Ludwig. 



Again, in 1863-4, this author published a paper in the ' Palasontographica,' 

 vol. xi, pp. 166, &c., on Unio pachyodon and three other species from various 

 formations ; Unio Kirnensis (being a form from the Coal-measures near Kirn, which 

 he says is very like U. Goldfussianus) , U. compressus, and U. fabseformis from the 

 Rothliegenden of Neurode. So that this author is responsible for twenty-three 

 forms of Unio and four forms of Dreissina from the Coal-measures. 



The genera Unio, Anodonta, Gyrena, and Cyclas may all be here considered as 

 synonymous with Carbonicola, and the author gives no reasons for this subdivision 

 of the genera. 



The majority of the originals of these figures are in the Geological Museum 

 at Dresden, and I was permitted by the kindness of Professor Geinitz to study 

 them there. I will first quote Professor Geinitz on the subject of Ludwig's papers, 

 which criticism appeared in 1864 as an addendum to a paper by Giimbel (to be 

 quoted later on in its chronological order) in the ' Neues Jahrbuch f . Min.,' &c, 1854, 

 p. 651, where he says, " On the whole, my conclusions upon the species of Unio 

 and Anodonta from the Coal-measures and Dyas, which Ludwig has so carefully 

 described, differ considerably from those of that learned author; " and he proceeds 

 to show that many of the forms are the same. The chief thing to be noticed on 

 comparing the originals with the drawings is the amount of invention and artistic 

 embellishment which have made crushed and damaged specimens appear as 

 perfect. In one case the fossil itself is invented, being only a concretionary mass 

 {Dreissina inflata, ' Palseontographica,' Bd. viii, t. lxxi, fig. 10). Many of the different 



