Cacuminostreptus, Mwabvu, Tarombera, Hamer, Michelle, Slotow, Rob & Barraclough, David, 2010

Mwabvu, Tarombera, Hamer, Michelle, Slotow, Rob & Barraclough, David, 2010, A revision of the taxonomy and distribution of Archispirostreptus Silvestri 1895 (Diplopoda, Spirostreptida, Spirostreptidae), and description of a new spirostreptid genus with three new species, Zootaxa 2567, pp. 1-49 : 31-32

Genus Cacuminostreptus gen. n. Mwabvu

Type species: Cacuminostreptus mazowensis sp. n.

Etymology: Name derived from the Latin word cacumen (a point, summit, top, spine) in reference to the spinous antetorsal and lateral metaplical processes of the gonopods.

Diagnosis: Proplicae spathulate (subapically/apically wide); lateral metaplical processes with abrupt narrowing along the length, distally spinous; proximad lobe present on lateral metaplical process; apical metaplical processes short; and antetorsal processes with a distal spine ( Figs 11a, 11b , 12a, 12b , 13a, 13b , 14a, 14b ).

Description: Large spirostreptid millipedes, body length 130–215 mm; maximum body width 9–15 mm.

Body rings 54–67.

Body black; legs and antennae brown.

Prebasilar plate of gnathochilarium reduced, without median sclerite.

Collum black, sometimes with anterior lobe, with 2–6 complete striae and 1–7 incomplete striae.

Pre-femoral process of 1st pair of male legs proximally rounded with laterally deflected apical extension ( Figs 11c , 12c , 13c , 14c ).

Sternum triangular; paracoxite apex horizontal or broadly rounded.

Proplicae about 2/3 of gonopod length, spathulate and setose apically ( Figs 11a , 12a , 13a , 14a ); subapical central depression of proplica flanked by raised edges. Medial lobe present on proplica apex, concealed under oral fold of metaplica.

Aborally, medial edges of metaplicae raised.

Apical metaplical processes and lateral metaplical processes short.

Lateral metaplical process arrowhead-shaped with a spine distally ( Figs 11a , 12a , 13a , 14a , 11b , 12b , 13b , 14b ). Lateral metaplical process may be tilted towards apical metaplical process or crescent-shaped distally.

Telopodite spirals after telopodite knee. Origin of antetorsal processes at telopodite knee. Antetorsal processes crescent-shaped, with a spine at extremity ( Figs 11a , 12a , 13a , 14a , 11b , 12b , 13b , 14b ). Postfemur of telopodite with three branches at extremity.

Distribution: Known from Mozambique; eastern, south-eastern, western and northern Zimbabwe; Kruger National Park, South Africa.

Remarks: The genus includes Archispirostreptus conatus ( Attems 1928) and three new species. Cacuminostreptus species are smaller than some species of Archispirostreptus . The gonopods of Cacuminostreptus species differ from Archispirostreptus species by having a shorter apical metaplical process, a lateral metaplical process with a constriction and arrowhead-shape, and an antetorsal process without spikes but terminating in a spine. In addition, the proplicae are wider subapically/apically. Unlike Archispirostreptus species which have been recorded from East, West and Central Africa, and the Middle East, Cacuminostreptus is known only from southern Africa. Based on Hoffman’s (2008) definition of the Spirostreptini, Cacuminostreptus also belongs to the tribe. A key to the genera of Spirostreptini is given below.

Figures

FIGURE 11 a, b. Cacuminostreptus conatus (NMZ / D 844). a, oral view of gonopods (without left telopodite); b, aboral view of gonopods.

FIGURE 12 a, b. Cacuminostreptus mazowensis (NMSA 21970). a, oral view of gonopods (without left telopodite); b, aboral view of gonopods.

FIGURE 13 a, b. Cacuminostreptus triangulatus (NMZ / D 568). a, oral view of gonopods; b, aboral view of gonopods.

FIGURE 14 a, b. Cacuminostreptus vumbaensis (NMZ / D 602). a, oral view of gonopods (without left telopodite); b, aboral view of gonopods.

FIGURE 11 c, d. Cacuminostreptus conatus (NMZ / D 844). c, oral view of prefemoral lobe of first pair of male legs; d, lateral view of collum.