ptera that secrete a viscid fluid which, on contact with the
air, hardens into a silken fibre.

Silvicolous: living in moist, shady woods.

Simple, Simplex: without process, armature, or appendage of any
kind.

Simple eyes: = ocelli; q.v.

Sinciput: in Coleoptera; that part of the vertex between the eyes.

Sinistrad: toward the left.

Sinistral: extending to or at the left from the median line.

Sinistro-caudad: extending obliquely from the left toward the tail.

Sinistro-cephalad: extending obliquely from the left toward the head.

Sinuate: cut into sinuses; applied to lines and margins with an in and
out curve.

Sinuated: winding: with the edge scooped into sinuses.

Sinuato-convex: sinuate and convex.

Sinuato-lobate: sinuate and lobed.

Sinuato-truncate: truncated, with the margin sinuate.

Sinuous: undulating; curved in and out.

Sinus: a curvilinear indentation more or less profound: an excavation
as if scooped out: a curved break in an otherwise straight margin.

Siphon: a tube-like mouth organ in certain insects: the breathing
tube of a Culicid larva: any tubular external process or structure.

Siphonaptera: an ordinal name for insects which are wingless: mouth
formed for piercing and sucking; saltatorial; transformations
complete: the fleas = Aphaniptera; q.v.

Siphonata: = Homoptera or, more specifically, plant lice and leaf
hoppers.

Siphonets: see honey tubes.

Siphonophora: = Coccinellidae; the term is preoccupied in the
Coelenterates.

Siphunculata: the sucking lice.

Siphunculus: the suctorial organ of a louse, contained within the
tubule: in plant lice =honey tubes; q.v.

Situ (in): in its natural place or position.

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