THE RULES OF NOMENCLATURE 357 



in the number of genera new kinds of names had to be 

 sought. Names of mythological characters, such as Venus 

 and Actceon, were appropriated, but have long been 

 exhausted. Then came more or less descriptive com- 

 pound words of Latin or Greek derivation, such as 

 Micraster (little star), and Macrodon (big tooth) : Many 

 genera were named in compliment to individuals, as 

 Murchisom'a and Lonsdaleia, or from the locality where 

 they were first discovered, as Amberleya, Bohemilla. As 

 the number of generic names increased enormously there 

 came a natural tendency to help the memory by com- 

 pounding similar names for genera in the same class; 

 thus the great majority of crinoid genera have names 

 ending in -crinns, those of many corals end in -phylltim or 

 phyllia, of many starfish in -aster, of cephalopods in -ceras, 

 of brachiopods in -thyris. But there is no copyright in 

 such endings and they must not be trusted as a necessary 

 indication of affinities. Thus Cryptocrinus is not a crinoid 

 but a cystid ; Holocystis, not a cystid but a coral ; Campto- 

 ceras and Platyceras are gastropods. Most names ending 

 in -obolus denote brachiopods, but Trochobolus is a sponge. 

 The attempt to combine the name of a man or a place 

 with one of these terminations has led to such uncouth 

 compounds as Agassizocrinus and Quenstedtoceras. 



It was at one time a rule that the generic name of any 

 fossil should bear the termination -ites. Thus a fossil 

 Nautilus was called Nautilites, not because it was thought 

 to belong to a different genus from the recent Nautilus, 

 but merely to emphasize its fossil state. This plan has 

 long been abandoned, but it has led to some confusion 

 in the case of genera entirely extinct. Many modern 

 authors have removed the termination in such cases, thus 

 Echinosphcerites has been altered to Echinosphcera. Un- 

 fortunately the same termination has been used as a 

 means of distinction between different genera Dalmanites 



