Accession Of Utility Atv How Do You Get The Accession Number Of Species(specifially Squirrels)?

How do you get the accession number of species(specifially squirrels)? - accession of utility atv

I need the serial number for certain types of squirrels, and instant messaging to find http://www.ncbi.nlm.nih.gov/ trying to find, but can not find anywhere else? or somewhere in there?