26 



ON THE CIIILOPODA OF NORTH AMERICA. 



S. LONGIPES, n. sp. — S. castauea, robusta ; capite castaneo, magno, scgtncnto ccphalico oyato, sparse minute 

 punctato, segmento basali maximo ; antennis 17 artieulatis; mandibulorum dente tuberculoque magnis; 

 laininis dentalibus margine antico fere recto; deutibusG, nigris, magnis, utrinque duobus intioiis coadu- 

 natis, externo sejuncto, conico ; scutis iuterduni postice viridi margiuatis; spiraculis anticis maximis ; 

 pedibus lutcolis, longis, compressis, paiis penultimi articulo basali spinis 5 in processu angulari terminali 

 alterisque 1 — 2 armato ; pari postremo valde elongato, subeylindrico, haud compresso, articulo basali 

 tibiali tnulto longiore, 30 — 45 spinis longiiudiualitcr seriatis arruato, processu angulari maguo, spinis 

 6 — 8; appendicibus aualibus lateralibus dense punctatis, elongatis, singula spinis apicalibus 8 — 12 

 et iuterduni alteris niarginalibus 1 — 1. 



This species is closely allied to S. alternans, Leach, but differs from the characters 

 given by Mr. Newport; first, in the mandibular tubercle (mandibular tooth of Newp.) 

 being very large and having the lesser tubercle near to its base ; secondly, in the 

 number of spines on the basal joint of last pair of legs being from 30 — 45 instead of 

 from 45 — 60, and finally by the roughness of the lateral anal appendages. Besides, 

 our specimens agree in possessing important characters not mentioned by Mr. New- 

 port, and which it is fair to conclude do not exist in his species. 



The head and its appendages are very large and stout. The antennae are gene- 

 rally lighter in color than the body. The first scuta is much the smallest. The 

 lateral margins of anterior scuta are straighter than those of the posterior, which are 

 elevated. The posterior margin of the terminal scutum is very strongly arcuate. The 

 scuto-episcutal sutures are traceable, but not so well marked as the sterno-episternal. 

 The femur of the nineteenth pair of legs is furnished with two small spines on its 

 distal extremity ; that of the twentieth with one or two on its upper surface, and a 

 well marked terminal angular process supporting five small spines. The femur of the 

 last pair is rather depressed than compressed, and armed with 30 — 45 small spines, 

 irregularly arranged in rows on its upper, inner and lower surfaces. Preanal scale 

 somewhat elongate, narrowed posteriorly. The specimen from " Halifax (?)" is pro- 

 bably incorrectly labelled ; possibly it may have been carried there in a cargo of 

 timber. 



Specimens belonging to the Smithsonian Institution. 



Probably incorrectly la- 

 belled as to locality. 



330 



T 



Ft. Jefferson, Garden 

 Key, Tortugas. 



Dr. D. D. Whitehouse. 

 Mr. Wurdeman. 





Unc. H 



209 



2 



Florida. 







" 3|—4 



194 



o 



Halifax, N. S. 



Dr. J. B. Gilpin. 





" 5 



S. byssina, Wood. — S. sautrate viridis aut brunnea, capite dilute castaneo, et labio mandibulisque sparse 

 punctatis ; segmento cepbalico late ovato, antice leviter emarginato, segmento prebasali nullo ; antennis 

 luteolis, 18 artieulatis, pubescentibus ; dente mandibulari gracile; laminis dentalibus latis ; dentibus labi- 

 alibus 10, parvis, nigris, utrinque tribus intimis coadunatis; pedibus gracilibus, luteolis, modice com- 

 pressis ; pari postremo supra complanato, subtus valde convexo, marginibus superioribus et externo ej 

 iuterno acutis ; articulo basuli tibiali longiore et intus et subtus bi vcl tri spinoso, processu angulari 



