ON THE CHILOPODA OF NORTH AMERICA. 15 



Gen. 2. BOTHROPOLYS,* (n. g.) 



Antennae multiarticulatae. Caput latum. Ocelli numerosi. Labium antice denticulatum, medio sulcatum, 

 eraarginatum. Coxarum exeavationes, parvi, fere rotundi punctiformesque, in seriebus 3—4 dispositre. 

 (Fig. G.) 



B. nobilis, n. sp. — B. brunneus, segmento cephalico postice margine elevato; antennis elongatis, sparse 

 pilosis, subsegmento impunctato, articulis basalibus 4 longitudine fere sequalibus ; laminis dentalibus 

 distinctis, margine antico subrotundato, angulis anticis externis subproduetis, denticulis 12 — 19 ; ocellis 

 utrinque 32 — 37; scutorum anticorum marginibus et posticis et lateralibus elevatis sed scutoruru posti- 

 corum lateralibus solum. 



The anterior scuta have their posterior margins almost straight and elevated. The 



labial teeth are generally large and acute, but rarely coadnate. The ^'sj^ 



number of pairs of eyes appears to vary, even in the adult, from 32 — 



37; perhaps 35 is the most common number. The feet are in most 



individuals of the same color as the body, but they are occasionally 



yellow. The posterior portions of the sterna are often furnished with 



stiff hairs. The articular spines are of moderate size. To show the 



variations in number of the labial teeth, we append the following list of the numbers 



in one lot from South Illinois : — 



6 specimens with 14 teeth each. 



3 " " 13 " 



1 specimen " 19 " " 



1 " " 15 " " 



The geographical range of this species is extensive. We have found it around 

 Philadelphia ; and it is in the Smithsonian collection, from Illinois and Missouri. 



265 

 344 



12 



1 



South Illinois. 

 St. Louis, 3Io. 



Specimens belonging to Smithsonian Institution. 



Lin. 8—12. 

 " 7—11. 



R. Kennicott. 

 Dr. Engelmann. 



B. Xanti, n. sp. — B. brunneus, segmento cephalico polito aurantiaco, margine postico elevato; antennis 

 -pilosis; ocellis utrinque 18; laminis dentalibus margine antico rotundato, denticulis 16 — 18, ni"ris, 

 acutis; scutis valde asperatis, alternis majoribus postice valde emarginatis, — alternis minoribus margine 

 postico fere recto sed angulis posticis acutis et valde productis. 



The head is rather large, with a curved suture running transversely from one set 

 of ocelli to the other, having its convexity directed posteriorly. The first scuta 

 approximates the head in color, has its posterior margin strongly raised, and is only 

 slightly roughened. The other large scuta are very rough, with (sometimes indistinct 

 but generally well marked) ruga?, converging towards the median line anteriorlv. 

 The last scuta is, however, without ruga?, and but slightly roughened. It is much 

 narrowed anteriorly and posteriorly, and somewhat elongate. Preanal sterna almost 

 circular, with two lateral curved impressions and a central shorter straight one, which 



* 0&po;, fovea; xcm/c, ruultus. 



