O.K., finally found an answer to this difficult question. Our dictionary defines species as:
"The basic unit used in classifying and describing living organisms. It ranks below the genus and above the individual or specimen, and denotes a group of individuals having common attributes, reproducing according to their kind, and designated by the conventional latinized 2-word name indicating first the genus and then the species; for example, Ilex Aquifolium (English holly) and Citrus sinensis (sweet orange)."
But experts do not agree whether to call the second name of the species — the specific epithet or the species. Honestly, I'm leaning to calling it the specific epithet because a species within a species is confusing, to say the least.
Like this:
"Scientific names follow a specific set of rules. Scientists use a two-name system called a Binomial Naming System. Scientists name animals and plants using the system that describes the genus and species of the organism. The first word is the genus and the second is the species. The first word is capitalized and the second is not. A binomial name means that it's made up of two words (bi-nomial). Humans are scientifically named Homo sapiens. You may also see an abbreviation of this name as H. sapiens where the genus is only represented by the first letter."
"The first word of the binomial is the genus name of the species, and the second word is the specific epithet for the species. For example (see figure above), the scientific name for the blue crab is Callinectes sapidus. Callinectes, the genus name, is the collective term which includes many species of crabs closely related to the blue crab. The specific epithet, sapidus, describes exactly which of the Callinectes species is being identified."
"Species names are binominal (i.e., consist of two words). The first word is the generic name. The second word has been called "specific name" or "specific epithet" -- but it is not the species name. Both words together are the species name."
"Species are identified by two names (binomial nomenclature). The first name is the genus, the second is the species."
Also found this explanation on Yahoo! Answers:
"Biologists, for some reason, have never been able to agree on what to call the second word in the name of a species. It has been called the species name, the trivial name, the species epithet, the trivial epithet, etc. The problem is that the full name of a species has to include two words, the name of the genus it belongs to, and the name of the particular species, OF THAT GENUS, that it belongs to. The second word, whatever it is, does not name any species if it is used by itself. The name of a human is Homo sapiens, but the word sapiens could be used to name species of any other genus, also. Thus if you say the species of an organism is sapiens you haven't named any particular species unless it is clear from the rest of the context that you are specifically referring to the sapiens that is in the genus Homo. It happens that sapiens is not a common second word in organism names. Others are, however. The word pallidus (-a, -um), meaning pale, had by 1961 been used as a name for 107 different kinds of spiders alone. No doubt it has been used for scores of other animals, as well."
So a big apology for causing all this confusion,
@zuzu!
