Sixth longitudinal vein: in Diptera; = 1st anal vein (Comst.).
Skeleton: the hard chitinous parts which externally (exoskeleton) or internally (endoskeleton) form a protective covering, or serve as points of attachment, to muscles and other soft organs.
Skippers: a popular term for Hesperid butterflies: the dipterous larva sometimes found in cheese and other provisions.
Slaty: very dark blackish gray with a reddish tinge [neutral with a little Indian red].
Slug: in general, any larva that has a slimy viscid appearance, and the body closely applied to the food plant: more specifically, the larvae of certain saw-flies and of some Coleoptera.
S. M. interspace: sub-median interspace in the primaries of Lepidoptera, includes the space between the median and sub-median veins; (cubitus and 1st anal, Comst.).
Smaltinus: a dull grayish blue.
Smaragdinus: emerald green [pale green].
Smooth: a surface without elevations or indentations.
Snout: the prolongation of the head in Rhynchophora at the end of which the mouth parts are situated: see rostrum.