1U 



THE MYRIAPODA OF NORTH AMERICA. 



Fig. 14. 



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 spe- 

 cies 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. 



Hub Fort Tcjon, California. S. Xantus. — Smithsonian Collection. 



S. SPINICAUDA. 



S. aurantiaca, polita; capite labio mandibulis sternisque profunde punctatis; segmento-cephalico subovato; 

 antennis pubescentibus; labii tnargine antico lato, fere recto, medio vix eruarginato; scutis modice rugosis, punc- 

 tatis, inarginibus lateralibus elevatis; pedibus postremis elongatis, gracilibus, spinis duabus S. sexspinosa; illis 

 siniilimis, 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; an- 

 tennae 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 punc- 

 tate; 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. o9. 



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. 



lliU. Washington Territory, Oregon. — Drs. Cooper and Kin- 

 nei |y, - Smithsonian ( 'ollection. 



Fig. 15. 



