Acrotrichis hammondi sp. n.

(Figs. 2 E, 16A–K)

Habitus Fig. 16A. Length 0.96 mm. Colour blackish, shining; antennae brownish yellow, the two basal segments slightly paler. Antennomeres 3–11 0.43 mm long Fig. 16 C. Width across eyes 0.36 mm. Mentum and submentum chaetotaxy Fig. 16 H. Pronotum 0.32 mm wide, 0.59 mm long, sides with a slight sinuation before the posterior angle Fig. 16 B. Elytra 0.51 mm long, 0.59 mm wide. Lateral posterior borders of mesoventral keel slope down moderately at shoulders and medially form an excision with a rounded point Fig. 16 I; sides of mesoventrum with scattered setae. Posterior margin of metaventrum and metacoxal plates Fig. 16 J.

Male: front tibiae very broad Fig. 16 K; ventrite five weakly excised medially with two groups of 3/4 spines on either side Fig. 16 F; ventrite six with an excision bordered laterally by two single prominent setae Fig. 16 F; ventrite seven distinctive Fig. 16 G; aedeagus Fig. 16 E.

Female: spermatheca Fig. 16 D.

Etymology. Johnson ms name in honour of Peter Hammond of the BMNH who collected some of the specimens and has always been very supportive both to Johnson and to myself.

Remarks. The male secondary sexual characters will immediately distinguish this species from all others. All the known specimens were taken in dung which may be the preferred the habitat. (No other Ptiliidae from dung have been encountered in this study of Madagascan species to date.)

Type data. Holotype: ♂, Perinet Forest, litter, 12.x.1970, P. Hammond (BMNH). Paratypes: 14 examples, same data as holotype (BMNH).