1904.1 NATURAL SCIENCES OF PHILADELPHIA. 651 



NEW CHILOPODS. 



BY RALPH V. CHAMBERLIN, 



Lithobius centurio sp. nov 



Dorsum dark brown, the principal scuta darkened along posterior 

 border and along middle; head a little lighter, darkened over middle 

 caudally; antennae light brown; legs mostly yellowish, the posterior 

 pairs becoming darker, brown; posterior portion of venter darkest, 

 all the scuta excepting the most anterior with a paler central circular 

 area. 



Body much narrowed anteriorly. 



Posterior angles of the 9th, 11th and 13th dorsal plates produced. 



Antennae of moderate length; articles 19-22, the distal ones, 

 excepting the ultimate, reduced. 



Ocelli 22, arranged in 5 series (2, 5, 6, 6, 1 + 2). 



Presternal teeth 2-2. 



Coxse of last two pairs of legs armed dorsally and also dorso-laterally 

 at the furrow, which is more dorsal in position than usual. Anal legs 

 with claw unarmed; spines 1, 3, 2, 1. Claw of penult legs armed with 

 a single spine; spines 1, 3, 3, 1. Spines of first legs 2, 3, 2. 



Coxal pores small, round, 3, 3, 3, 3. 



In the male the femur of the anal legs is abruptly produced into a 

 lobe at its distal end above, and the tibiae is produced into a larger lobe 

 at its proximal end above adjacent to the femoral lobe, the lobe being 

 truncate above and somewhat bent distally. The penult legs have 

 the tibia produced into a moderate lobe at its distal end. 



Length 14 mm.; width of 10th dorsal plate 2.6 mm. 



Locality. — Las Vegas, New Mexico (Prof. T. D. A. Cockerell). 



One male. 

 Lithobius cookerelli sp. nov. 



Brown to chestnut, head darkest, some dorsal scuta in one specimen 

 with the posterior margin lined with dark and with a dark stripe along 

 middle; antennae concolorous with head or but little paler; legs light 

 brown. 



Angles of none of the dorsal plates produced. 



Antennae moderately long, articles 28-29, in length long and mod- 

 erate. 



