Description. Male holotype. Length 2.3 mm, width 1.6 mm; body oval, elytron with side weakly rounded, wider than pronotal base, widest at middle of elytra. Dorsal surface shiny except elytron with trace of microsculpture. Color black; head with base of frons and vertex black, remainder of head yellow (Fig. 527); pronotum black with lateral margin narrowly yellow in basal ½, yellow area projected inward in apical ½; elytron blue (Fig. 525); antenna, legs yellowish red; apical maxillary palpomere dark brown; epipleuron dark reddish brown; abdomen with basal ventrite brown, ventrites 2–4 brown medially, yellow laterally, ventrite 5 yellow. Head punctures small, separated by a diameter or less; pronotal punctures as large as on head, separated by a diameter or less; elytral punctures larger than on pronotum, separated by a diameter or less; prosternal punctures large, sparse, nearly absent, mesosternal punctures large, separated by a diameter or less; metasternal punctures as large as on mesosternum separated by less than a diameter on basal and lateral borders, small, nearly absent medially; abdomen with punctures on ventrites 1–3 large, separated by a diameter or less, punctures on remaining ventrites smaller, separated by about a diameter. Head with frons weakly widened from vertex to clypeus, 1.4 times as wide as eye measured at vertex; eye canthus short; apical maxillary palpomere short, widened from base to apex. Pronotum widest at middle, reflexed lateral margin narrow, equal in width from base to apex. Epipleuron flat, slightly widened in basal ½, as wide as pronotal hypomeron, with feeble depressions for reception of femoral apices. Prosternum longer than wide, longer than mesosternum, anteriorly produced, base weakly arcuate, lateral carina narrow, extended nearly to prosternal apex. Postcoxal line on ventrite 1 long, slightly angulate, extended 2/3 distance to ventrite apex (Fig. 526). Apex of ventrite 5 arcuate. Genitalia with basal lobe longer than paramere, comparatively narrow, widest medially, lateral margin weakly curved from base to apex, apex not emarginate; paramere straight, slender, equal in width to rounded apex, without marginal serrations (Fig. 528), sipho lost.

Female. Similar to male except head all black with apex of frons narrowly yellow. Female genitalia with spermathecal capsule slender, slightly wider in basal ½, apex of cornu rounded.

Variation. Length 1.8–2.6 mm, width 1.4–1.7 mm, width of pale lateral pronotal margin variable, some specimens nearly all black, others with distinct, narrow yellow border, basal lobe of male genitalia somewhat variable in width and length.

Type material. Holotype male; BRAZIL: Guanabara, Rio de Janeiro, X.1963, M. Alvarenga coll. (USNM). Paratypes; 6, 1, same data as holotype; 3, bamboo scales, Rio De Janeiro, iv.14’39, P.A. Berry; 1, Brasil. Rio de Jan., Corcovado, X.1959, Seabra e Alvarenga. (USNM). 1, CORCOVADO, Guanabara Brasil, IX.1966, Alvarenga e Seabra. (DZUP).

Remarks. Prodilis sandy is distinguished from P. kristi by more intensely blue elytral surface, lateral pronotal margin more narrowly pale, and basal prosternal margin not medially emarginate. This species and P. kristi may represent the same species with differences noted here only intraspecific variations.