358 PALAEONTOLOGY 



was so named, for instance, because its original form 

 Dalmania was preoccupied. Hence no rule of universal 

 application can be laid down for such cases, unless it be 

 the strict rule of priority. 



If a sub-generic name is needed it is written in paren- 

 theses after the generic name; thus Lichas (Corydocephalus) 

 anglicus denotes that the species belongs to the sub-genus 

 Corydocephalus of the genus Lichas.* 



The best trivial name is a simple Latin adjective, 

 either descriptive of some feature of the species (as in 

 Dalmanites caudatus, Belemnites minimus) or indicating the 

 locality where it was first found (as Crania parisiensis, 

 Lichas hibernicus, or the much less pleasing oystev- 

 mouthensis and czenstochovensis). The adjective must 

 always agree in gender with the generic name, and must 

 be altered if necessary with a change in the latter. 

 Instead of an adjective a noun may be used " in apposi- 

 tion " according to Latin usage, when it keeps its own 

 gender, as Psiloceras planorbis (wrongly altered by some 

 authors to planorbe as though it were an adjective), 

 Agnostus rex, Rhynchonella vespertilio. Thirdly, it may be 

 a noun in the genitive case, usually (but not always) a 

 personal name, as Lingulella davisi, Asteroceras smithi. The 

 rules of the International Zoological Congress only allow 

 a person's name to be made into a trivial name by the 

 addition of the letter *, thus not only insisting on some 

 dreadful barbarisms,! but tending to cause great con- 



* Square brackets are sometimes used for a different purpose 

 the name which they enclose is not a part of the correct specific 

 name, but is a reminder that a change of name has taken place 

 thus, Basilicus [Asaphus] tyrannus recalls the fact that Basilicus 

 tyrannus has long been known as Asaphus tyrannus, and is an assist- 

 ance to those who might fail to recognize a familiar species under 

 a new generic name. 



f For instance, Zaphrentis omaliusi (instead of omalii). But reasons 

 for making this rule will be found in the Introduction to Bronn's 

 Index Palaontologicus. 



