1. The ordinal number of sixty-four in counting order
   - sixty-fourth

See also: ordinal

• genus Spadella
• genus Spalax
• genus Sparaxis
• genus Sparganium
• genus Sparmannia
• genus Spartina
• genus Spartium
• genus Spathiphyllum
• genus Spergula
• genus Spergularia
• genus Spermophilus
• genus Sphacele
• genus Sphacelotheca
• genus Sphaeralcea
• genus Sphaerocarpos
• genus Sphaerocarpus
• genus Sphagnum
• genus Sphecius
• genus Sphecotheres
• genus Spheniscus
• genus Sphenodon
• genus Sphyraena
• genus Sphyrapicus
• genus Sphyrna
• genus Spilogale