Genus Macroxenodes Silvestri, 1948

TYPE SPECIES. — Polyxenus meinerti Silvestri, 1898 .

REDEFINITION OF THE GENUS

Trichomes short and thick.

Setiform sensilla with three spines on antennal articles, with three or four spines on prefemora, femora and tibiae.

Head: eight ocelli on each side. Vertex with one pair of posterior tufts not separated from the anterior tufts and consisting of two rows (anterior and posterior).

Antennal article VI with five or more sensilla basiconica, one setiform sensillum between the two anterior sensilla basiconica and one sensillum coeloconicum on the distal row of sensilla basiconica (Figs 4E, D; 7C, D; 9C, E). Antennal article VII with two short, thick sensilla basiconica, one setiform sensillum between them and one sensillum coeloconicum posterior (Figs 4C; 7B; 9B). Three trichobothria of equal size with cylindrical funiculi (Figs 4A; 7E).

Whole area of labrum clothed with numerous small and varied cuspidate papillae (also called cuticular setae), in addition to two to six rows of larger spherical papillae (Figs 5A; 7F; 9D) and armed with lamellar teeth on anterior margin. Outer palpus of gnathochilarium with sensilla pseudoarticulated at apex and middle palpus with pseudoarticulated sensilla except for 7-9 short antero-median sensilla.

Trunk: two lateral tufts of trichomes on each tergite connected by trichomic rows. Tergites II to VIII or IX with three trichomic rows: an anterior row with trichomes directed anteriorly towards the head, a median and a posterior row directed towards the telson. The posterior row is sinuous and uninterrupted; trichomes of middle row more spaced than in the anterior and posterior rows (Fig. 11C).

Legs: setae on coxae, trochanters and prefemora with subcylindrical, elongated, naked funiculi (Figs 5F, G; 7J). Other small, oval setae (= setiform sensilla) on prefemora, femora and tibiae (Figs 5D, E; 7H, I). Tarsi II with one seta ending in a point (Figs 5H; 7K; 9F). Pretarsus bearing an anterior process with a spinous projection slightly longer than the claw and posterior lamellar process longer than the claw, with thickened and pleated basal part.Claw with two strongly pointed and subequal anterolateral and posterolateral teeth (Figs 5I; 7L; 9G).

Telson: two latero-dorsal penicilli of hooked trichomes joined side by side. Dorsal face of telson with a few barbate trichomes a, one oval-shaped group composed of barbate trichomes c and one barbate antero-internal trichome b (Fig.6D).Ventral face with a subrectilinear row of barbate trichomes (v: Fig. 6C, E) located on edge of penicillus of hooked trichomes, usually with two to three hooks (Fig. 6B).