ON THE CIIILOPODA OF NORTH AMERICA. 29 



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. sub- 

 spinipes is furnished with five spines on its posterior pair of legs ! The specimens 

 before us may belong to S. ornata, but their heads do not differ from those of S. sub- 

 spinipes, and we cannot understand what the armature of S. ornata really consists of. 

 We have seen two specimens from San Francisco, belonging to the Museum of Com- 

 parative Zoology. 



Besides the North American Species, the collection of the Smithsonian Institution 

 contains the following : 



S. viridicornis, Newp., Ann. and Mag. N. H., p. 97, sp. 12 ; ot Linn. Trans, xix. p. 897, pi. 3, f. 1, 3, 4, 5, 

 et pi. 40, f. 5, 6; et Catal. Brit. Mus., Myriapoda, p. 45. 

 S. Ilopei, Newp., MSS. 

 S. viridicornis, P. Gervais, Apteres, iv. p. 287. 



169 | 1 | Paraguay. | ('apt. T. J. Page, U. 8. N. | | Unc. G | 



S. azteca, Saussure, Mem. Societ. Phys. Genev. 1860, xv. p. 382, f. 41. 



We think that S. maya is probably the young of this species, although we have 

 never seen a specimen of it. We would also call attention to the close relationship 

 (if they are not identical) between S. azteca and S. varia, Newp. 



306 | 2 | La Union. | Capt. Dow. | | Unc. 3 | 



S. modesta, n. sp. — S. brunnea ; capite modico, lscve, segniento-cephalico postice subtruncato, magno, pre- 

 basali nullo, basali magno; antennis 21 articulatis; labio impunctato; laminis dentalibus antice angus- 

 tatis; dentibus labialibus 8 — 10, utrinque duobus aut tribus intimis leviter coadunatis, uno aut duobus 

 extimis sejunctis ; pedibus compressis; pedibus postremis subrobustis, elongatis, supra eomplanatis, 

 subtus valde convexis ; articulo basali, marginibus superioris et externo et interno subacutis sed haud ele- 

 vatis, intus 4 — 6 spinis in serie duplici, subtus spinis 8 — 9 in serie triplici, processu angulari quadri- 

 fido; articulo tibiali basali fere asquali, marginibus superioribus interdum subelevatis; appendicibus 

 analibus lateralibus brevibus, punctatis, singula spinulis apiealibus 2 — 3 et interdum niaro-iuale 

 altero. 



That part of the cephalic segment which is anterior to the eyes is generally of a 

 lighter color than the remainder. The internal labial tooth on each side is sometimes 

 obsolete. The scuto-episcutal and sterno-episternal sutures are well marked. The 

 anterior scuta have the lateral margins straight and not elevated, whilst the posterior 

 five or six have them arched and elevated. Most of the scuta are abruptly truncate 

 posteriorly. The penultimate is very large and broad, and, like the corresponding- 

 sterna, has a circular shape, but is truncate anteriorly and posteriorly. The breadth 

 posteriorly of the terminal scuta is nearly twice its length. The preanal scale is sub- 

 cpjadrate and very much narrowed. This species is closely allied to S. varia, Newp., 

 but differs from Mr. Newport's description, in not having the cephalic segment small, 

 in the labial teeth not being minute, in the color, in the size, and. finally, in the 



