THE HYRIAPODA OF NORTH AMERICA. 



163 



vinced me that that naturalist had a specimen with reproduced hind feet ; yet it is worth 

 while to append his description, so that the correctness or incorrectness of this opinion 

 may he more easily shown.* Length 2i inches. 



TABLE SHOWING VARIATIONS IN SPECIFIC CHARACTERS. 



Hah. Illinois.- — It. Keunicott. — Smithsonian Collection. — Massachusetts Museum Comparative Zoology. 



S. LONGIPES. 



S. castanea, robusta; capite castaneo, ruagno; segmento cephalico ovato, sparse minute punctata: segmento 

 basali maximo; antennis 17 articulatis; mandibulorum dente tuberculoque magnis ; laminis dentalibus marginc 

 antico fere recto; dentibus 6, nigris, magnis, utrinque duobus intimis coadunatis, externo sejuncto, conieo; scutis 

 interdum postice viridi marginatis; spiraculis anticis maximis; pedibus luteolis, longis, compressis, paris penultimi 

 articulo basali spinis 5 in processu angulari terminali alterisque 1 — 2 arruato; pari postremo valde elongato, sub- 

 cylindrico, baud compresso, articulo basali tibiali multo longiore, 30 — 45 spinis longitudinaliter seriatis armato; 

 processu angulari magno, spinis G — 8 ; appendicibus analibus lateralibus dense punctatis, elongatis, singula spinis 

 apicalibus 8 — 12 et interdum alteris marginalibus 1 — 4. 



Chestnut, robust ; head chestnut, large; cephalic segment ovate, sparsely minutely punctate; basal segment 

 very large ; antennas 17 articulate ; mandibular tooth and tubercle large ; dental laminae with their anterior margin 

 almost straight ; teeth 6, black, large, the two inner on each side coadnate, the external distant, conical ; scuta 

 sometimes margined posteriorly with green; anterior spiracles very large ; feet yellowish, long, compressed, basal 



* " S. ineqdidentc (S. inyequidens). — Tete subcordiforme un peu-elargie ; doubles stries dorsales paralleled 

 continues en dessus, assez peu marquees; bord posterieur du dernier segment triangulaire obtus; stries inferieurs 

 faiblement divergentes ; plaques des segments subarrondies a leur bord posterieur; plaque preanale quadrilatere 

 etroite a bord posterieur plus etroit que I'anterieur, droit; angles subarrondis; pieces later ales terminees en opine 

 multifide tres-finement ponctuees ; antennes longues, nues ; sallies dentiferes finement ponctuecs, ;\ trois dent 

 inegales, l'interne large, a bord Iibre rectiligne, la mitoyenne peu distincte, subarrondie, Texterne separee par un 

 espace plus grand ; pieds de derriere assez longs, forts, subarrondis, epineux en dessous et a la face interne ; 6 

 epines environs en dessous ; et a. peu pros 14 au bord interne, la derniere multifide, a sept petites pointes inegales 

 en couronne. Couleur ferrugineuse un peu nuancee de verdatre ; antennes pities ; tote, segment forcipulaire et 

 partie posterieur plus ferrugineuse. Longcur de corps, 0.190; plus grande largcur, 0.022. xVntennes, 0.035 ; 

 pieds de derriere, 0.035." 



" Pes Etats Unis, a New- York, par M. Milbert (Museum de Paris, 1824)." 



