THE MYRIAPODA OF NORTH AMERICA. 



167 



Iutcolis, levitcr compressis; pari postremo gracile, artioulo basali supra complanato, subtus valdc convoxo et sine 

 spina, intus biapinoso, margins superiorc externo acuto ; proccssu angulari valde elongato, simpliee vol bifido ; 

 artioulo tibiali basali fere aoquale, sed suboylindrico et graeiliore ; appendioibus analibus lateralibus longis, dense 

 minute profunda 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; antennae 19 articulate, distally pubescent; labium slightly 

 convex, without sutures, minutely punctate ; dental laminae 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 coadnatc, the outer two separate ; scuto-cpiscutal 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. BISPINIPBS, 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 lamina? 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 8. Newportii, Lucas (originally described by Mr. Newport as 8. Oervaisii). Mr. New- 

 port, in his latin diagnosis, both in the Linnacan Transactions and the Catalogue of the 

 British Museum, says " dentibus compicuis" 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 I" What docs he mean % This species is also allied to 

 8. 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 8. 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 8. subspinipes, and it is not clear what the armature of 8. ornata really con- 

 sists of. I have seen two specimens from San Francisco, belonging to the Museum of 

 Comparative Zoology. 



