S. maculaticeps.
S. sordide aurantiaca, polita; corpore robusto, subsemicylindrico, antice modice attenuato; capite modice parvo, obscure saturate rubro, minute albomaculato, in lateribus sparse piloso; antennis longis, leviter pubescentibus, haud acuminatis; mandibulis crassis, obscure quadridentatis, pilis paucis; denticulo antico utrinque magno, conico; labio inipunctato, antice vix emarginato, medio canaliculato; pedibus modice longis, gracilibus, subcompressis, utrinque 77, et superficie ventrali sordide flavis; scutis lgevibus sine suturis; sternis lgevibus, suturis sterno-episternalibus valde impresses et plerumque postice depressionum subovatarum transversarum pari; pedibus postremis ("stylis analibus") (in mare solum ?) robustissimis, supra subcomplanatis, subtus convexis, acuminatis.
Dirty orange, polished; body robust, subsemicylindrical, anteriorly moderately attenuate; head rather small, obscurely deep red, minutely spotted with white, sparsely pilose on the sides; antennæ long, lightly pubescent, not acuminate; mandibles thick, obscurely quadridentate, with a few hairs; anterior denticule on each side large, conical; labium impunctate, anteriorly scarcely emarginate, medianly canaliculate; feet rather long, slender, subcompressed, on each side 77, together with the ventral surface dirty yellow; scuta smooth, without sutures; sterna smooth, strongly impressed with the sterno-episternal sutures, and generally with a pair of irregularly ovate, transverse depressions; last pair of feet ("anal styles") (in male only?) very robust, above subcomplanate, below convex, acuminate.
S. maculaticeps, Wood, Journ. A. N. S., new series, vol. v, 1863, p. 48.
The cephalic segment is slightly narrowed anteriorly, and the upper surface of the whole head is marked with very small whitish dots. The anterior and posterior extremities of the body are perhaps a little darker in color than the intervening portion. The inferior aspect of the head is of the same color as the superior, contrasting with the under surface of the body. Near the posterior border of each sterna there is a pair of subequal oval transverse depressions. The legs are almost destitute of hair, having occasionally, however, a few very short ones. Length, 2½ inches.
Hab. Upper Colorado. H. B. Mollhausen.—Smithsonian Collection.
S. laticeps.
S. dilute aurantiaca; capite magno, impunctato; segmento cephalico lato, breve, transverso, quinqueangulato, segmentis basali subbasalique marginibus curvatis et angulis anticis prolongatis; antennis brevibus, crassis, cylindricis, antice pubescentibus; labio breve, nonnihil convexo, haud canaliculato; mandibulis parvis, singula intus denticulo obtuso indistincto; pedibus subcompressis, gracilibus, utrinque 81, pari postremo (in mare solum ?) non-nihil crasso, cylindrico, haud acuminato, coxis magnis; sternis depressione lineari-ovata transversa et suturis sterno-episternalibus signatis; squama preanali valde canaliculata, postice valde emarginata, angulis posticis subacutis.
Light orange; head large, impunctate; cephalic segment broad, short, transverse, quinqueangulato; basal and subbasal segments with their margins curved and anterior angles prolonged; antennæ short, thick, cylindrical, anteriorly pubescent; labium short, somewhat convex, not canaliculate; mandibles small, each with an indistinct obtuse tooth on inner surface; feet subcompressed, slender, 81 on each side; last pair (in male alone?) somewhat thickened, cylindrical, not acuminate, with large coxæ; sterna marked with a transverse linear-ovate depression
