9i6 PRINCIPLES OF STRATIGRAPHY 



described and named Fusus meyeri, a modern species, and Aldrich 

 in 1886 described a Tertiary species as Fusus meyeri. Reference to 

 the former would thus be made as follows : Fusus meyeri Dunker 

 1869 (non Aldrich 1886). Since Aldrich considered his species a 

 true Fusus he was forced to change its name on discovering that 

 the name had been preoccupied for that genus. So in 1897 he pro- 

 posed the name Fusus ottonis for this species. It appeared, how- 

 ever, that Aldrich's species is not a true Fusus, but belongs to a 

 series of distinct origin. The name Falsi fusus (Grabau) was, 

 therefore, proposed for it, with the present species as the type, 

 and, since this genus has no other species by the name of meyeri, 

 it became proper to retore that specific name to its original rank. 

 Thus we now have the synonymy of this species as follows (omit- 

 ting references to authors which did not change the name) : 



Falsifusus meyeri — (Aldrich) Grabau. 



1886 Fusus meyeri Aldrich * 



not Fusus meyeri Dunker, 1869 



1897 Fusus ottonis Aldrich 



1904 Falsifusus meyeri Grabau 



In this case the specific name ottonis not only becomes a syno- 

 nym, but, so far as Fusus is concerned, it is dead and cannot be 

 used again, even for a new species of Fusus. Unless this rule is 

 observed much confusion is likely to arise. Should the generic 

 name Falsifusus be found invalid, however, the type species Falsi- 

 fusus meyeri being proved a true Fusus after all. the specific name 

 ottonis will have to be restored to its original rank, the species in 

 question being then Fusus ottonis. The general rule is that no spe- 

 cific name which has become a synonym in a genus can ever be 

 used again for another species of that genus, though it may be 

 used for species of other genera. If an old comprehensive species 

 is divided into a number of species the original name is retained 

 for that subdivision to which it was originally applied, or to which 

 the diagnosis corresponds most closely. For the other subdivisions 

 new names must be proposed. If two authors describe the same 

 species under different names, the name given in the earlier de- 

 scription is retained, the other one becoming a synonym. If a spe- 

 cies is transferred from one genus to another, in which there is 

 already a species of that name, that one of the two species to which 

 the specific name in question was first applied retains it, while the 



* The dotted lines take the place of the reference to the literature where 

 this name was used. 



