LINGULA. 51 



while adopting the term Koninckii in preference to the apocryphal one of 0. speluncaria, 

 simply mentioned in the German edition of Sir H. de la Beche's 'Manual ' (1832). 1 



Family— LINGULID.dE. 



(Vide Introduction, Vol. I, p. 133 ; and Appendix, p. 8.) 

 Lingula credneri, Geinitz. Plate IV, figs. 30, 31. (King's Monog., pi. vi, figs. 25 — 27.) 



Lingula credneri, Geinitz. Versteinerungen des Zechsteingebirges, p. 1], pi. iv, 

 figs. 23—29, April, 1S48. 



A small oval shell, rarely exceeding 5 lines in length, by 3^ in width. The valves 

 are very slightly convex, thin, and marked by numerous raised lines of growth. 



This species has been well described by Dr. Geinitz, Professor King, and Mr. Howse. 

 It is found in the marl slate of Ferry hill, Thrislington Gap, and Trickley. Mr. Howse 

 possesses a bivalve example, in which the attenuated beak of the ventral valve is clearly 

 exhibited. It may still remain a question to be determined hereafter, whether this form 

 did not also occur in the Carboniferous period, for it is very difficult to separate several 

 species of Lingula, which closely resemble each other. L. Credneri is not a rare fossil, 

 either at Ilmenau or Corbusen, in Germany. 



' It is a Catalogue name, which Goldfuss communicated to Von Decken for the German translation, 

 and all that is said consists of " Orbicula speluncaria, Schlotheim, Gliicksbrunn." But the name is 

 nowhere to be found in any of Schlotheim's numerous Memoirs, and it is probable that Goldfuss took the 

 denomination from Schlotheim's collection, and nothing warrants the assertion made that it is the same as 

 that dedicated by Geinitz to M. De Koninck. It was mentioned by M. De Verneuil as " un corps tres 

 douteux," in the ' Bulletin de la Societe Geologique de France,' vol. i, 2d ser., p. 504, 1844, and might be 

 a little Patella, or anything else than a Discina, for all we know ; and therefore we feel in justice bound 

 to adopt the name given by Geinitz, as the species was first described and illustrated by him. 

 Catalogue names are so injurious to the progress of science, that their introduction cannot be too strongly 

 deprecated, nor can they ever claim priority over any subsequent description or illustration of the same 

 object by another author. 



