of S. sexspinosa, but further investigations may show that that of this form also darkens with age. The prebasilar fold is generally well marked. The scuto-episcutal sutures are distinct; the sterno-episternal absent; but a suture marking the line of coalescence of the primitive sterna is often very apparent. This species is closely allied to the preceding as well as to the following. It differs from both in the shape of the anterior margin of the labium (Fig. 14), in the scarcity of punctations on the body, and in the pubescence of the distal portion of the last pair of feet. The superior spine of the lateral anal appendages is perhaps a little larger than in S. sexspinosa, but certainly smaller than in S. spinicauda. The white blotches beneath the posterior feet are common to all the North American species. Length, 2 inches.
Hab. Fort Tejon, California. S. Xantus.—Smithsonian Collection.
S. spinicauda.
S. aurantiaca, polita; capite labio mandibulis sternisque profunde punctatis; segmento-cephalico subovato; antennis pubescentibus; labii margine antico lato, fere recto, medio vix emarginato; scutis niodice rugosis, punctatis, marginibus lateralibus elevatis; pedibus postremis elongatis, gracilibus, spinis duabus S. sexspinosæ illis similimis, articulo basali tibiali longiore; appendicibus analibus lateralibus valde elongatis, rude punctatis, singula spina apicali unica alteraque in angulo posteriore superiore; squama preanali modice breve, postice rotundata, vix emarginata. (Fig. 15.)
Orange, polished; head, labium, mandibles, and sterna profoundly punctate; cephalic segment subovate; antennæ pubescent; anterior margin of the labium broad, almost straight, medianly scarcely emarginate; scuta moderately rugous, punctate, with elevated lateral margins; last feet elongate, slender, with two spines very similar to those of S. sexspinosa; basal joint longer than the tibial; lateral anal appendages very elongate, rudely punctate; each with a single apical spine, and another upon the posterior superior angle; preanal scale rather short, posteriorly rounded, scarcely emarginate.
S. spinicauda, Wood, Journ. A. N. S., 1863, new series, vol. v, p. 39.
Fig. 15
The head is deeply punctate. The scuta are somewhat rugous with the scuto-episcutal sutures traceable. The sterna are without any traces of sutures. The whole body is more or less deeply punctate. The superior posterior angle of the lateral anal appendages is slightly prolonged and armed with a rather small black spine, which is, however, considerably larger than in any other species known to me. The posterior legs are exactly like those of S. sexspinosa, Newp. Length, 2 inches.
Hab. Washington Territory, Oregon.—Drs. Cooper and Kinnerly.—Smithsonian Collection.
