Oxypyge varicolor Silvestri, 1896

Bond, Jason E. & Marek, Paul E., 2003, Rhinocricidae Systematics I: The taxonomic placement of the species of Zipyge Chamberlin, 1925 and Oxypygides Chamberlin, 1922 (Diplopoda: Spirobolida: Rhinocricidae: Oxypyginae), Zootaxa 292, pp. 1-8 : 3-4

Oxypyge varicolor Silvestri, 1896 ( Figs. 1– 6 )

Material examined: Three male and three female specimens from Panama, Pearl Island, coll. J.P.E. Morrison, 23 Aug 1944 (deposited in U.S. National Museum), det. by R. Hoffman 23 February 1960.

Male: Coloration of preserved material: head, antennae, and collum very light yellowish brown ( Fig. 4 ). Collum slightly darker with lighter margins. All other segments distinctly banded. Prozonite light cream color, metazonite dark brown with light cream colored posterior margin.

Antennae with numerous sensory cones, flattened laterally, incrassate distally. 10–10 labral setae, clypeal groove dark and distinct, 37 ocelli. Width 3.36 (1)–3.48 (16)–3.32 (45), 47 ring segments. Distinct scobinae on segments 7–31, diminishing in size posteriorly. Tarsi lacking ventral pads. Epiproct short, not extending beyond paraprocts. Anal valves elongate, with dorsal hook ( Figs. 5 ). Hypoproct long, triangular with blunt terminal end, not extending beyond paraprocts.

Anterior and posterior gonopods illustrated in Figs 1–3 . Sternum narrow distally ( Fig. 2 ), coxae (Cx) and telopodite (Tp) as in other related rhinocricids ( Fig. 1 ). Posterior gonopod telopod (Tp, Fig. 3 ) long and spatulate distally with a membranous interior. Seminal canal (Sc) visible extending from the coxae (Cx) to the solenomere (Sm). Seventh segmental ring posteroventrally modified as a postgenital bar to accommodate gonopods ( Fig. 1 ). Posterior gonopods in situ extending ~2.0 mm from gonopodal cavity.

Female: Coloration as described for males. Antennae with numerous sensory cones, 10–10 labral setae, clypeal groove distinct, 36 ocelli. Width 3.87 (1)–4.35 (20)–3.35 (48), 50 ring segments. Scobinae not formed as distinct pits but appearing on ~8th segment as a dorsal pair of light scars, much less prominent than in males. Anal valves and terminal ring segments as in males ( Fig. 6 ).

Remarks: Oxypyge at present comprises eleven species distributed primarily throughout Guatemala and Panama. Though no diagnosis exists, Silvestri’s (1896) description and illustration of Oxypyge is not sufficient to confidently ascertain the concept of the genus. However, references to the elongate anal valves and the depiction of a spatulate posterior gonopod indicate that Chamberlin’s (1922 and 1925) subsequent placement of a number of Central American species in the genus was probably justified. Kraus’ placement of the Peruvian species, O. tingomariae Kraus, 1957 , in Oxypyge seems biogeographically and morphologically questionable. Although the anal valve conformation illustrated by Kraus depicts a morphology similar to that of Oxypyge ; though the anterior and posterior gonopod morphology, particularly that of the solenomere (very robust), does not support placement of this species in the genus. Moreover, anal valve modification is ubiquitous throughout Rhinocricidae and is likely very plastic among taxa—thus not a feature that should be used alone as a synapomorphy for a genus.

Figures

FIGURES 1 ­ 6. Oxypyge varicolor Silvestri, 1896. 1, anterior gonopod, posterior view. 2, anterior gonopod, anterior view. 3, left posterior gonopod. 4, lateral view of male anterior segments, arrow points to gonopods. 5, posterior segments, male. 6, posterior segments, female. [Scale bar = 1.0 mm (Figs. 1 – 3)]