luteolis, leviter compressis; pari postremo gracile, articulo basali supra complanato, subtus valde convexo et sine spina, intus bispinoso, margine superiore externo acuto; processu angulari valde elongato, simplice vel bifido; articulo tibiali basali fere æquale, sed subcylindrico et graciliore; appendicibus analibus lateralibus longis, dense minute profunde punctatis, utrinque spinis apicalibus 1—3.
Olive, polished; head olive-chestnut; mandibles large; cephalic segment broadly ovate, anteriorly slightly emarginate, the basal segment large, prebasal absent; antennæ 19 articulate, distally pubescent; labium slightly convex, without sutures, minutely punctate; dental laminæ broad, short, with their anterior margins straight, the external posterior angles produced; denticules 10, conical, small but acute and distinct, the inmost three on each side closely coadnate, the outer* two separate; scuto-episcutal sutures not conspicuous, but the sterno-episternal rather so; feet yellowish, slightly compressed; last pair slender, the basal joint above complanate, below strongly convex and without spines, within bispinous, the superior external margin acute, the angular process very elongate, simple or bifid; tibial joint about equal to the basal, but subcylindrical and more slender; lateral anal appendages long, densely minutely profoundly punctate, on each side with from 1—3 apical spines.
S. bispinipes, Wood, Journ. A. N. S., New Series, 1863, p. 28.
The length of cephalic segment is equal to its breadth. The mandibles are thick. The breadth of the dental laminæ much exceeds their length. The teeth are small, but very distinct. The penultimate scutum is large, with its lateral margins strongly arched; the terminal is large, with its lateral margins arched, very strongly elevated, and its posterior very arcuate. The preanal scale is not canaliculate, but much narrowed posteriorly, with its margins very nearly straight. The spines on the basal articulation of the last pair of feet are very large; the anterior is situated above the other. This species is closely allied to S. Newportii, Lucas (originally described by Mr. Newport as S. Gervaisii). Mr. Newport, in his latin diagnosis, both in the Linnsean Transactions and the Catalogue of the British Museum, says "dentibus conspicuis" but in the former work he says, "The most marked character of this species is the indistinctness of the labial teeth, which in some specimens are entirely wanting!" What does he mean? This species is also allied to S. ornata, Newport. That author states, "pedum paris postremi articulo basali spinis tribus acutis," but does not state the form of the head. Afterwards he says: "This is a very beautiful species, very distinct in every respect of form, size, and shape of the head from S. subspinipes, but precisely similar as regards the shape and armature of posterior pair of legs," &c. Now, S. subspinipes is furnished with five spines on its posterior pair of legs! The specimens before me may belong to S. ornata, but their heads do not differ from those of S. subspinipes, and it is not clear what the armature of S. ornata really consists of. I have seen two specimens from San Francisco, belonging to the Museum of Comparative Zoology.
