Macroxenodes meinerti
Creators: name: Duy-Jacquemin, Monique Nguyen
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Diplopoda
Polyxenida
Polyxenidae
Macroxenodes
Macroxenodes meinerti

description: Macroxenodes meinerti (Silvestri, 1898)
(Figs 4-6)
Polyxenus meinerti Silvestri, 1898: 53.
MATERIAL EXAMINED. — Venezuela. LosTeges (Caracas), Meinert, 12.VI.1891, 2 ad. ♀♀ (nos. 1 and 3), 1 ad. ♂ (no. 2) syntypes “Cotypes” (ZMUC).
REVISED DESCRIPTION
Coloration: white-yellowish, due to prolonged preservation in alcohol.
Measurements: Body length (without caudal penicillus): syntypes females 3.90 and 4.00 mm; syntype male 3.60 mm. Caudal penicillus length 0.90-1.00 mm.Tarsus II of 13th leg: female 176 µm, male 153 µm long.
Head: Eight ocelli on each side. Vertex with one pair of posterior tufts consisting of two rows: anterior row with 15 or 16 trichomes, posterior row with 8-13 trichomes, last trichome in front of internal trichobothrium (Fig. 4A). Distance between tufts small.
Proportions of antennal articles as shown in Figure 4B; length/diameter ratio of article VI = 1.6-2.0. Antennal article VI with 12-16 dorsal sensilla basiconica: two anterior (E: Fig. 4E) thicker and shorter than the others (sometimes the first anterior longer than the second) (E: Fig. 4D); one proximal sensillum coeloconicum c above third or fourth anterior sensillum basiconicum; one trifid setiform sensillum s between two short anterior sensilla E, but more basal (Fig. 4D, E). Antennal article VII with two dorsal sensilla basiconica: posterior one shorter than anterior; one posterior sensillum coeloconicum and one trifid setiform sensillum between the two sensilla basiconica (Fig. 4C). Three trichobothria of equal size, with cylindrical funiculi (Fig. 4A).
Entire surface of labrum with numerous, small, cuspidate papillae in addition to two or three anterior rows of spherical papillae (Fig. 5A); 15-17 lamellar teeth on anterior margin. Clypeo-labrum with 12 or 13 setae along posterior margin. Outer palpus of gnathochilarium with 16 sensilla pseudoarticulated at apex and middle palpus with 20 (male: Fig. 5B) or 21 sensilla (females), comprising 14 long pseudoarticulated sensilla and 7 short, nonarticulated sensilla at apex.
Trunk: except on collum and tergite X, trichomes arranging in two lateral tufts with 15-36 trichomes connected by three uninterrupted trichomic rows (Fig. 11C): anterior row with 13-21 trichomes (male), 17-23 and 19-35 (females) directed towards the head; middle row with 11-26 trichomes and sinuous posterior row with 25-48 trichomes directed towards telson (see Fig. 4A). On some tergites the anterior and middle rows are slightly sinuous. No middle row on tergite IX except in female no. 3. Total number of tergal trichomes as follows: I (collum), 70-93; II to VIII, 84-153; IX and X, 58-99. Lateral protuberance of tergite I with 4 or 5 trichomes in a row (l.p: Fig. 4A).
Legs (Fig. 5C): all articles of legs with sensory setae, except first tarsus. Coxa, trochanter and prefemur each bearing a seta with an oval base furnished with apical acute process (Fig. 5F, G). Chaetotaxy as follows: coxae I with one seta, II- XIII with 2 to 5 setae (except 6 setae on left VI in one female and 1 seta on XIII in male); trochanters with 1 seta; in male, prefemora of legs I and XIII with 1 seta, those of legs II-XII with 1 seta and 1 or 2 small, trifid, aligned setae; in females, prefemur of leg I with 1 seta, those of legs II-XIII with 1 seta and 2 or 3 (4 and 1 in three cases) small, trifid or quadrifid aligned setae (Fig. 5D); almost all femora and tibiae with same small seta as prefemur (Fig. 5E). Second tarsus with a small seta as shown in Figure 5H. Telotarsus bearing an anterior process with a spinous projection slightly longer than claw, two subequal latero-anterior and posterior spiniform processes; posterior lamellar process thickened and pleated basally (Fig. 5I).
Three or four setae above anal valve in females.
Male: all areas of penis with cuticular setae and about 10 small, oval setae. Coxal glands on legs VIII and IX.
Telson: 10 and 12 trichomes a (male: Fig. 6D), 12-14 (females); one trichome b inner to group of 23 or 24 (male), 12 and 17 (female no. 1) trichomes c (Fig. 6D). Ventral face with a subrectilinear row of 9 and 7 barbate trichomes v in male (Fig. 6C), 5-7 in females paratypes located on edge of penicillus of hooked trichomes, usually with two hooks (Fig. 6B).
AFFINITIES
Macroxenodes meinerti is very similar to M. bartschi (Chamberlin, 1923), which was redescribed by Nguyen Duy-Jacquemin & Condé (1984). The two species differ only in the number of sensilla on the outer expansions of the gnathochilarial palpi (16 in meinerti, versus 13 in M. bartschi) and the number of anterior rows of spherical papillae on the labrum (only in 3 meinerti, as opposed to 4 or 5 in M. bartschi).
description: Published as part of Duy-Jacquemin, Monique Nguyen, 2009, Revision of the genera of Polyxenidae bearing pseudoarticulated gnathochilarial sensilla (Diplopoda, Polyxenida, Polyxenidae), with the description of two new species, pp. 829-848 in Zoosystema 31 (4) on pages 835-839, DOI: 10.5252/z2009n4a5, http://zenodo.org/record/4520337