20 



ON THE CHILOPODA OF NORTH AMERICA. 



Specimens belonging to the Smithsonian Institution. 



Brownsville, Texas, 1853. 



Ringgold Barracks. 



Western Texas. 



Northern Texas. 



Texas. 



Fort Bliss, New Mexico. 



West of San Antonio. 



New Weid, Texas. 



Fort McKavit, Texas, 



Red River, Ark. 



Eagle Pass. 



Fort Chadbourne, Texas. 



Matamoras, Tamaulipaa, 



Eagle Pass. 



Monterey, New Leon. 



Sonora and Chihuahua. 



Fort Towson, Red River, Ark. 



New Orleans to Galveston. 



Ilermes. Sonora. 



Chihuahua Trip. 



Bet. San Antonio and El Paso. 



New Brunfels, Texas. 



Fort Smith, Ark, 



Red River, Ark. 



Santa Fe. 



Fort McKavit. 



Southeastern Texas. 



Fort Buchanan, Arizona. 



Near 38° L. 



?Texas. 



Fort Mason, Texas. 



Calcasieu Pass. La, 



Ringgold Barracks. 



En route from N. O. to Galveston. 



Lieut. Couch, U. S. A. 



? 



S. Hayes. 



Dr. Jones. 



Dr. S. W. Crawford, TT. S. A. 



R. G. 



Prof. Ervendberg. 



Capt. Plummer. 



Cipt. Marcy. 



R. G. Scho'tt. 



Dr. Swift. 



Lieut. Couch, U. S. A. 



R. G. Schott. 



Lt. Couch, U. S. A. 



Major W. H. Emory, U. S. A. 



Dr. L. A. Edwards, U.S.A. 



E. B. Andrews. 

 Or. T. If. Webb. 

 Dr. T. H. Webb. 

 T. D. Graham. 

 Mr. Lindheimer. 

 Mr. Sluimard. 

 Capt Marcy. 

 Mr. Howard. 

 Dr. W. H. Anderson. 



Dr. Irvin. 



Lt.E. G. Beckwith, II. S.A. 



Major ,1. II. Thomas. 

 G. Wurdeman. 

 R. G. Schott. 

 E. B. Andrews. 



R. Schott. 



A. Schott. 



S. polymorpiia, Wood. — S. olivaceo brunnea, capite dilute castaneo ; segmento ceplialico subovato, postice 

 subtrunoato fere impunctato, antennis oOarticulatis; dente mandibulari tuberculo basali magno; dentibus 

 labialibus 8 maximis, duobus intiniis utrinque coadunatis, externis sejunctis; scutis interdum margine 

 posteriore nigro-viride, niarginibus lateralibus pleruraque liberis ; pedibus postremis robustis, supra 

 subcotnplanatis; articulo basali, et medio subdepresso, intus 3 — 7 spinis, subtus 10 — 18 spinis in serie 

 quadruplici (interdum inordinatim) dispositis, processu angulari aut bifido aut trifido aut quadrifido; 

 appendicibus analibus lateralibus singula 4 — 8 spinis apicalibus et altera marginali. 

 S. pohjmorpha, Wood, Proc. A. N. S. 1861, p. 11. 



The prebasilar fold is apparent but connate with the rather large basilar segment. 

 The first segment of the body is very small; the scuto-episcutal suture barely trace- 

 able, but the sterno-epistermal much more distinct. In a few individuals the labial 

 teeth are small and coadnate. The color shades off from that given above to a tes- 

 taceous chestnut. This species is alosely allied to S. hero*, and perhaps a differential 

 diagnosis would not be amiss. The most important difference is in the number of 

 joints to the antenna). Owing to the ease with which these animajs lose portions of 

 these organs, the want of the typical number is not to be relied on in the identification 

 of individuals. Another character which also is often not available for individual 

 identification, but which characterizes this species, is the small size attained to. The 



