Spirobolus umbobrochus Keeton 1960

Spirobolus umbobrochus
Diagnosis. — Distinguished from all other species of the genus by the rounded (in caudal view) prefemoral endite which has a notch in its mesal margin. Differs from bungii and walkeri in having a longer, less concave posterior telopodite with a larger unsclerotized distal pad. Distinguished superficially from formosae by the details of the lateral corners of the second segment.
Description. — Described from three male specimens, one of which is in very poor condition.
L 80, 92 mm.; W 7.1, 8.1 mm.; L/W 11.3, 11.4.
Face broad in two specimens, the lateral edges of clypeus only slightly exceeded by second segment of antenna; face narrow in one specimen, the lateral edges of clypeus much surpassed by second segment of antenna. Lateral corners of clypeus relatively distinct, antennal groove thus well-defined anteriorly; groove not well defined posteriorly, the parietal sclerite almost flat. Mandibular cheek only very slightly grooved ; distal margin of stipes always concave, the concavity somewhat V-shaped but not deep. Eyes per patch 30, 32, 34, 37, 37, 37. Clypeal setae 7, 8, 8; labral setae 12, 13, 13.
Paranota of collum relatively long, their ends broadly rounded (right paranotum of one specimen abortive) ; anterior margin of collum abruptly angled at level of eye patches ; margining ridge faint. Second segment only slightly surpassing ends of collum, its production not knob-like but, rather, forming a thick, rounded carina running along anterior two-thirds of ventrolateral margin.
Anal valves only moderately compressed ; anal lips distinct but only moderately prominent.
First and second legs shorter than other legs. Coxae of male legs 3-7 with short rounded or subtruncate processes, each bearing a large seta. Third seg59
merits of legs 3-7 slightly longer than second segments ; claws less than one-half (sometimes less than one-fourth) as long as last podomeres. Postgenital legs unmodified, with few ventral setae (e.g. 1 or 0, 1, 0, 0, 0, 1).
Mesal process of sternum of anterior gonopods longer than broad. Mesoventral corners of coxal endites more rounded than in biingii or walkeri. Posterior telopodite relatively long and not as concave as in hungii or walkeri, with a large unsclerotized distal pad. Prefemoral portion of telopodite large but without the distinct mesal shoulder seen in bmigii and walkeri. Prefemoral endite appearing subcircular in caudal view, with a shallow notch in its mesal margin.