Bacteria and Viruses 95 



Rule 25. Sect. 6. Rejection and Replacement of Names 



RULE 25. A specific or subspecific epithet is illegitimate in the following 

 special cases and must be rejected: 



a. When it is merely a word not intended as a specific epithet. 



b. When it is merely an ordinal adjective used for enumeration. 



c. When it exactly repeats the generic name (tautonym). 



d. When it is a later homonym within the same genus, that is, when it 

 duplicates a specific epithet previously and validly published for a 

 species of the same genus based upon a different type. 



e. When it was published in a work in which the Linnaean system of binary 

 nomenclature for species was not consistently employed. 



ANNOTATIONS 



Rule 23. Note that this rule governs only certain special cases. A 

 specific epithet is illegitimate also if it contravenes any rule of the 

 Bacteriological Code, that is, it is illegitimate if its author did not 

 use the earliest legitimate epithet available for the taxon being named. 

 Rule 23a. Authors sometimes do not completely identify by name 

 an organism described, but use an expression such as Clostridium sp. 



(species) . The expresssion means that the author regards the or- 

 ganism as belonging to the genus Clostridium, but with species in- 

 determinate. The word species is "merely a word not intended as a 

 specific epithet." In some fields of biology, particularly in botany, 

 the pronominal adjective "qualis" (some kind of) , also "novus" 



(new) , have been used in place of a specific epithet before a suitable 

 epithet has been decided upon. The use of qualis and novus in this 

 sense does not preclude their use if desired as specific epithets, as in 

 Bacterium qualis Steinhaus 1941 and Plectridium novum Huss 1907. 



Rule 23b. Authors in some cases have used ordinal adjectives instead 

 of specific epithets, particularly in enumeration of several new species. 

 The sixth species of the genus Bacillus might be termed Bacillus 

 sextus. Sextus as here used is not a legitimate specific epithet. This 

 illegitimacy does not extend to the intentional employment of ordi- 

 nal adjectives as specific epithets. There is a Bacillus tertius Henry 

 1916 and a Clostridium sex turn Prevot 1940. 



Letters of the Latin or Greek alphabet have sometimes been used 

 in the enumeration of new species and subspecies, as Bacillus a, 

 Bacillus h, etc. Letters thus used do not constitute legitimate specific 

 epithets, although specific epithets such as delta, alpha, etc. may be 

 legitimate. An "Opinion" relating to the Zoological Code states that 

 "serial letters, as a, b, c, etc. are not acceptable as specific names." 



