Part 135

Sigmoid: shaped like the Greek letter sigma, or English S.

Signate -us: = with marks or spots; see notate.

Signature: a colored blotch of any size or shape.

Silaceous: = ochraceous.

Silk: the hardened salivary secretion of certain larvae, mainly of Lepidoptera. similar material is produced by anal glands of some larva in Neuroptera.

Silk-glands: a pair of modified salivary glands in certain larva, mostly of Lepidoptera 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.