Sordid: dirty; dull.
Spadiceous: bay brown [dragon's blood + brown ochre].
Spado: the worker or neuter in bees and ants.
Sparse: scattered: single hairs, scales or sculptures set well apart.
Spatha: a median piece in male genitalia of aculeate Hymenoptera, covering the bases of the sagitte.
Spatula: the breast bone (q.v.) of cecidomyid larvae.
Spatulate: rounded and broad at top, attenuate at base.
Specialization: the adaptation of an organ to a definite purpose, or of an organism to fit a determinate environment.
Species: an aggregation of individuals alike in appearance and structure, mating freely and producing young that themselves mate freely and bear fertile offspring resembling each other and their parents: a species includes all its varieties and races.
Specific character: a feature common to all individuals of a species, by means of which they may be distinguished from all other individuals of other species: = essential character.