S. rubens.† Pairs of feet 50.
S. Whitei† Pairs of feet 76.
Ord. II. DIPLOPODA.
Each fully developed segment of the body provided with two pairs of feet.
Sub Ord. STRONGYLIA.
Mouth furnished with jaws suitable for the mastication of vegetable matters.
Fam. POLYDESMIDÆ.
Sternum and scutum of each segment fused together into a complete ring. Body composed of few segments; each furnished with lateral laminæ.
Gen. Polydesmus.
Lateral pores on the 5—7—9—10—12—13—15—16—17—18—19 scuta.
Subgenus Polydesmus.
Dorsum complanate. Lateral laminæ large, horizontal.
P. setiger.[1] Scuta with minute, obtuse, tuberculoid scales (sometimes obsolete) with a
row of acute, conical, seta-tipped tubercles along the posterior border.
P. granulatus.[1] Scuta covered with convex, obtuse, tuberculoid scales, arranged in four
more or less irregular transverse series; none of them seta-tipped.
P. hispidus.† Scuta with scales in five series.
P serratas. Scuta with 9 — 10 complanate scales, arranged in two series, besides a third obsolete series.
P. Canadensis. Color brown. Scuta with 8 scales, arranged in two series.
P. cerasinus. Color cherry-red. Scuta like in P. Canadensis.
Subgenus Paradesmus.
Dorsum moderately convex. Lateral laminæ large, horizontal.
P. erythropygus. Olive-chestnut; scuta with a large orange spot on their posterior surface. Lateral laminæ orange. Anal scutum broad, prolonged.
P. hispidipes. Olive-brown, immaculate. Anal scutum triangular.
Var. ? Ornamented with small orange spots. Lateral laminæ orange.
Subgenus Fontaria.
Dorsum convex. Lateral laminæ large, depressed.
P. Virginiensis. Chestnut, with yellowish lateral laminæ.
