What's the good name?
by Gary Rosenburg
In the June  Conchatenations
I discussed how to track down literature where mollusks were
named. Once the publications are in hand, one must be able to
determine if a name is available, that is properly published
according to the rules of the International Commission on Zoological
Nomenclature (ICZN), and if it is valid, the correct name for
a taxon. First I'll consider availability of names.
For an ink-on-paper work to be
considered published, it must be issued publicly for permanent
scientific record; it must have been obtainable free of charge
or for purchase at the time it was first issued; and it must
have been produced in an edition of numerous, identical, simultaneously
obtainable copies. Names that do not fulfill these criteria
are manuscript names and are not available, for example, new
species names proposed in an unpublished thesis. Also, names
cannot be made available by electronic publication, such as
World Wide Web pages on Internet, or CD-ROM.
The combination of a generic
and a specific name is called a species name. Conus gloriamaris
is a species name, Conus a generic name and gloriamaris a specific
(or trivial) name. Specific and subspecific names together are
called "species-group" names. For a species-group
name to be available, it must be binominal and spelled in Latin
letters. Binominal means having a two part name containing generic
and specific names. Subgeneric names are allowed to intervene
between the generic and specific names. Trinominal names are
allowed in the case of subspecies. If a hyphenated or compound
word is used as a species-group name, the hyphen or space is
eliminated and the parts of the word fused (e.g., "gloria-maris"
Names below the subspecies level
(infrasubspecific names) are not available. All varietal and
form names introduced after 1960 are infrasubspecific, by ICZN
rule. Varietal and form names introduced before 1961 are interpreted
as subspecies names unless the author's intent was clearly infrasubspecific.
Sometimes intent is obvious, for example, this monster of a
name: Littorina saxatilis rudis var. rudissima var. aurantia
Dautzenberg & Fischer, 1912. Here "aurantia" and
"rudissima" are obviously infrasubspecific. In other
cases, infrasubspecific intent is inferred when an author ignores
homonymy by applying the same form or varietal name to congeneric
species in the same paper, e.g., Anachis costulata var. major
Locard, 1897 and Anachis haliaeeti var. major Locard, 1897.
A third type of infrasubspecific name is illustrated by the
following pair: Voluta ancilla typica Lahille, 1895 and Voluta
ancilla ponderosa Lahille, 1895. By the former name Lahille
meant Voluta ancilla ancilla, but the convention of nominotypical
subspecies name had not yet been established. This might also
happen with names like "normalis" and "genuina."
Also not available are names introduced explicitly for teratologies
(monstrosities) and hybrids. If the author did not know that
he was naming a teratological or hybrid specimen, then the name
A name must also be accompanied
by some means of identifying it, either a description or an
illustration or a reference thereto for names published before
1931; or, after 1930, a description that states characters thought
to differentiate the taxon, or a reference to such a statement.
That is, before 1931, linkage to either a description or picture
is sufficient to name a species; after 1930, a description must
be present or referred to. A name that does not fulfill these
criteria is a "nude name" (nomen nudum in Latin) and
is not available. (Currently, the rules of zoological nomenclature
recommend but do not require a picture to name a species!)
Why so much emphasis on determining
whether names are available? Because names that are not available
cannot be valid names and they cannot preoccupy other names.
So, unless one is doing a complete nomenclatural review of a
group, names that are unavailable can be disregarded as historical
Next, from the set of available
names, one must determine which names apply to which species.
I will assume that one has a good grasp of the species itself,
that is, one has identified the object in nature and is trying
to determine its correct name. Sometimes careful study of original
descriptions and illustrations is sufficient to determine what
species a name refers to. In other cases one must track down
type specimens in order to see what species an author meant.
(Types are the original specimens on which a species or subspecies
name was based.) A name that cannot be identified, usually because
the type material is lost or in poor condition, is a dubious
name (nomen dubium in Latin).
Once having determined which
names apply to a particular species, one has identified a set
of synonyms. Synonyms are names thought to apply to the same
taxon. For species-group names, objective synonyms are based
on the same type specimen, so the synonymy is a fact; subjective
synonyms are based on different type specimens, so the synonymy
is an opinion that the type specimens belong to the same species.
For genus-group names, objective synonyms have the same type
species, subjective synonyms have different type species.
From a set of synonyms, the correct
name is usually the oldest name -- the senior synonym. This
name is said to have priority. The other names are junior synonyms.
Exceptions to the rule of priority are made when a junior synonym
is so widely used that it would threaten the stability of nomenclature
to resurrect an unused senior name, and in cases of homonymy.
Homonyms are identical names.
For genus-group names to be homonyms, they must be identical,
letter for letter. Species-group names that have the same derivation
can have minor phonetic differences and still be homonyms, for
example Helix sulfurea Hombron & Jacquinot, 1841 and Helix
sulphurea C. B. Adams, 1849 are homonyms. Senior homonym refers
to the name introduced first, junior homonym to the one named
later; the later name is said to be preoccupied.
Primary homonyms are identical
species-group names first introduced in the same genus. For
example, Mitra gracilis Reeve, 1844 is a primary homonym of
Mitra gracilis Lea, 1841. A junior primary homonym is permanently
invalid, so Cernohorsky replaced Mitra gracilis Reeve with Cancilla
gloriola Cernohorsky, 1970. Secondary homonyms were named in
different genera, but later came to be classified in the same
genus. If a junior secondary homonym was replaced before 1961
it is permanently invalid; if it was replaced after 1960 it
is reinstated if the species are no longer considered congeneric.
For example, Pustularia mariae Schilder, 1927 is usually classified
as Cypraea mariae, which is a secondary homonym of Cypraea camelopardalis
var. mariae Schilder, 1924. The name Cypraea mariae was replaced
by Cypraea mantellum Walls & Burgess, 1980. Cypraea mantellum
is the valid name for the species if it is placed in the genus
Cypraea. Because the name was replaced after 1960, if it is
placed elsewhere than Cypraea, however, the name reverts: thus
Lorenz and Hubert (1993) correctly use the name Annepona mariae.
The name Cypraea mariae must not be used.
The concepts of valid and available
are often confused. A valid name is the correct name for a taxon.
Many names that are available (i.e. properly published) are
invalid because they are junior homonyms or junior synonyms.
Usually one can decide objectively whether a name is available,
but whether a name is valid is more subjective, because it can
depend on the current state of knowledge, and whether one is
a lumper or a splitter. Among available names, junior primary
homonyms and junior objective synonyms are permanently invalid
-- they will always be homonyms or synonyms. Junior secondary
homonyms and junior subjective synonyms are invalid, but might
become valid if ideas of classification change.
Note that the current name for
a taxon is not necessarily valid. For example, Cochlespira elegans
(Dall, 1881), a turrid from Florida, is a current name, but
it is not a valid name. Dall named the species as Pleurotoma
(Ancistrosyrinx) elegans. The name is preoccupied by Pleurotoma
elegans Defrance, 1826 (and also de Blainville, 1829, Scacchi,
1835, Melleville, 1843 and Emmons, 1858). So why did I use Cochlespira
elegans in my Encyclopedia of Seashells? Because no other name
is available for the species, and my book wasn't the place to
fix the problem.
Note that a species can have
more than one valid name, because different authors can place
it in different genera. Cypraea aurantium and Lyncina aurantium
are both valid names for the Golden Cowrie, and Cypraea mantellum
and Annepona mariae are both valid names for Marie's Cowrie.
Only one name, however, can be valid for a species in a given
system of classification. The rules of nomenclature allow one
to determine the correct name for a particular species given
the current state of knowledge and ones own beliefs about classification.
Because of the rule of priority
for synonyms and homonyms, it is essential to know the correct
date of publication for names. One often finds discrepancies
of a year or two in the year cited for publication, particularly
for names from the 19th century. Such discrepancies usually
arise because the date on the title page of a journal or book
is not the true date when a name was published. For example,
in the 1850's the Proceedings of the Zoological Society of London
ran as much as three years behind. The Proceedings for 1851
were published in three parts, one each in 1852, 1853, and 1854.
In other cases, works were issued in parts, and the title page
bears the date of issue of the last part. Often, external sources
must be consulted to determine the true date of publication
of particular pages on which species names appear. Evidence
for dates of publication is most often found in the records
of receipts in libraries.
Among the bibliographic sources
cited in my previous column, Sherborn's Index Animalium is extremely
reliable for dates of publication, as Sherborn intensively researched
external sources of information and gives month of publication
if known. Ruhoff's work is unreliable for dates, as she generally
ignored external evidence. Goto & Poppe, being based on
secondary sources, is not reliable for establishing true dates
of publication. Knowing the true date of publication of a name
is not merely an academic exercise: if two synonymous names
were published in the same year, the one published first, even
if by a single day, has priority.
The Academy of
Natural Sciences of Philadelphia, Department of Malacology,
Benjamin Franklin Parkway, Philadelphia, PA 19103- 1195.