Otostigmus brevidentatus Verhoeff, 1937

Lewis, John G. E., 2014, A review of the orientalis group of the Otostigmus subgenus Otostigmus Porat, 1876 (Chilopoda: Scolopendromorpha: Scolopendridae), Zootaxa 3889 (3), pp. 388-413 : 393

Otostigmus brevidentatus Verhoeff, 1937

( Figs 12–20 )

Otostigmus (Otostigmus) brevidentatus Verhoeff, 1937 , 212, Pl. 13, Fig. 8. Malacca [ Melaka] Malaysia. Otostigmus brevidentatus: Verhoeff, 1942 , 185 (in key).

Diagnosis. Length 39 mm. Antennal articles 20, the basal 2.75 glabrous. Forcipular coxosternal tooth-plates with 11+8 small teeth. Tergites with paramedian sutures, marginate from 8, without keels or spinules. Paramedian sutures occupying anterior 50% of sternite. Coxopleuron with three apical and one lateral spine. Legs 1–19 with one tibial and two tarsal spurs. Ultimate leg prefemur with four spines in proximal half and a corner spine. Ultimate leg without tarsal spur.

Material examined. ZSM. Holotype on two slides, the first with head, antennae, mandibles, maxillae and first six segments, the second with segments 19, 20 and 21, one ultimate leg and one leg 20 (detached). Trunk segments 7 to 18 missing. Labelled Otostigmus brevidentatus Verh. [Plus Valley, Kuala] Perak, Malakka.

Description. (Verhoeff’s (1937) data in parentheses where relevant). Length 39 mm. Antennal articles 19[r]–20, the basal 2.75 glabrous dorsally ( Fig. 12 ), 2.4 ventrally (2 2/5 almost glabrous). Second maxillae with a poorly developed spur on article 2 ( Fig. 13 ). Accessory spine present on right pretarsus ( Fig. 14 ), left pretarsus reduced ( Fig. 15 ). Forcipular coxosternal tooth-plates very wide and low, ratio of width to length 2.5:1 with 11+8 small teeth ( Fig. 16 ). The dorsal surface with about 16+20 setae only seen as this is a cleared specimen. Right forcipular trochanteroprefemoral process with six small lenticular denticles ( Fig. 17 ), the left with two ( Fig. 18 ).

(Tergites with paramedian sutures, marginate from 8 otherwise smooth. Paramedian sutures occupying anterior 50% of sternites). Right coxopleural process damaged and repaired with one lateral spine, the left with three apical, one very small lateral and no dorsal spine ( Fig. 19 ) (3 end spines and one “oben” by which is meant anterior to).

First pair of legs missing, 2 to 6 and 19 with one tibial and two tarsal spurs, 20 and 21 without. (Legs 1 to 18 with two tarsal spurs, 19 to 21 without these, anterior legs with tibial spurs). Ultimate leg prefemur with VL 2, VM 2 spines in proximal half and a corner spine ( Fig. 20 ) (with only four spines).

The spiracles of segments 3 and 5 very small and apparently without tracheae as compared to the spiracle of segment 20 which has relatively extensive tracheae.

Remarks. Verhoeff (1937) noted that O. brevidentatus runs down to O. multidens in Attems’ (1930) from which he differentiated it by the higher number of coxopleural teeth (incorrect) and ultimate legs with four as compared to 7–12 prefemoral spines in O. multidens . It has, in fact, four plus a corner spine as opposed to (6) 7–12 plus a corner spine in the O. multidens . . Otostigmus brevidentatus certainly appears to be closely related to O. multidens . It may be differentiated by having only four prefemoral spines plus a corner spine, the forcipular trochanteroprefemoral process denticles and possibly a different nature of the forcipular coxopleural tooth-plates. These are, however, only known from the specimen mounted in Canada Balsam. It is here regarded as a separate species.

Figures

FIGURES 12 – 20. Otostigmus brevilabiatus Holotype. 12. Antennal article 3 dorsal. 13. Distal articles of left second maxillary telopodite. 14. Pretarsus of right second maxillary telopodite. 15. Pretarsus of left second maxillary telopodite. 16 Forcipular coxosternal tooth-plates. 17. Right forcipular trochanteroprefemoral process. 18. Left forcipular trochanteroprefemoral process. 19. Right coxopleural process. 20. Prefemur left ultimate leg ventral. FIGURES 21 – 26. Otostigmus foveolatus Holotype. 21. Antennal articles 1 – 3 ventral. 22. Antennal article 3 dorsal. 23. Pretarsus of second maxillary telopodite. 24. Forcipular coxosternal tooth-plates and right forcipular trochanteroprefemoral process. 25. Right coxopleural process. 26. Ultimate leg prefemur. Scale bars = 0.5 mm except Figs 22 & 27 = 1.0 mm and Figs 15, 16, 20, 21 & 24 = 0.1 mm.