PALEONTOLOGY. 405 



After Suess and Hyatt had opened the gates for the 

 creation of new generic names, the palaeontological literature 

 of the Cephalopods was inundated by innumerable new genera 

 and species, most of them only narrowly denned. The 

 number of species increased in a short time to several 

 thousands. At the same time, new genealogical tables were 

 constantly being constructed, and were as often a little altered 

 and a little improved. The leaders in this extreme movement 

 of breaking up the genera and species are Hyatt, Mojsisovics, 

 and Buckmann. 



The Aptychus and Anaptychus remains were the cause of 

 much controversy. Many authors, for example, Scheuchzer, 

 Walch, D'Orbigny, and Pictet, had supposed these plates to 

 be the shells of Cirripedes ; Parkinson and Schlotheim had 

 explained them as Lamellibranchs, De Luc and Bourdet as 

 the jaw-bones of some fish, while Hermann von Meyer had 

 ingeniously explained them as parasites of the Ammonites. 

 Ultimately it was universally accepted that they were es- 

 sential parts of the Ammonites, and they were sometimes 

 looked upon as the internal shells of Dibranchs or Am- 

 monites, sometimes as cover-plates of Ammonites. The 

 latter view, originally advanced by Riippel, has been con- 

 firmed by recently discovered specimens. 



Among the Dibranchs, the fossil Belemnites and the forms 

 nearly related to them have received a fair amount of 

 attention in palaeontological literature. For many centuries 

 Belemnites had been known and had passed under various 

 designations, "thunderbolts," " devil's-fingers," "lynx-stones," 

 "Lyncurium," etc.; Agricola described them and gave 

 illustrations, and from his time onwards they had a place 

 among the known "petrefactions," although the older authors 

 referred to them as "Echinid" needles, or other organism, or 

 sometimes thought them merely mineral structures. Ehrhardt 

 was the first to compare Belemnites with the shells of Nautilus 

 and Spirula, and De Luc pointed out their resemblance to the 

 enclosed shells of Sepias. The large work of Knorr and 

 Walch contains a good account of Belemnites, and a memoir 

 by Faure-Biguet (1810) gives numerous illustrations of 

 species. 



The influence of zoological advances was first clearly shown 

 in the suggestive paper by J. S. Miller (1826) published by 

 the London Geological Society. Soon after, two very good 



