1906.1 NATURAL SCIENCES OF PHILADELPHIA. 



A NEW LITHOBIUS FROM COLOEADO. 



BY RALPH V. CHAMBERLIN. 

 Lithobius harrietse sp. nov. 



Diagnosis. — Angles of the 9th, 11th, and 13th dorsal plates produced ; 

 articles of antennae 36; ocelli 11-12 in 3 series; prosternal teeth 2-2, 

 3-3; spines of first legs beneath 1,3,1, of penult 1,3,3,1 with 2 claws, of 

 anal 1,3,3,0 with 2 claws; coxal pores in 1 series, round, 4,6,6,5; length 

 11.5 mm. 



Description. — Dorsum brown with a l^lack or blackish median longi- 

 tudinal stripe; head paler especially anteriorly; antennae brown or 

 yellowish-brown, paler distally; legs yellow; venter yellow, darkest 

 over middle portion. 



Head wider than long (85 : 78), widely truncate or slightly incurved 

 behind, lateral margins moderately convex behind posterior ehd of 

 eye patch, then converging to bases of antennae, anterior margin of 

 head between antennae substraight; two furrows extending trans- 

 versely between eyes concave anteriorly, the posterior one usually 

 giving off two branches which converge caudally and meet in a point 

 on the median line; each posterior lateral portion of head marked with 

 one or several sharply impressed curved lines. 



Ocelli arranged in an oblong patch in three series ; 11 or 12 in number, 

 1 -1-4,4,2(3); single ocellus large, vertically elliptical; first eye of upper 

 row larger than others excepting the single one. 



Antennae short, consisting of 36 articles of short length, the ultimate 

 conical, in length about equalling the two preceding together; articles 

 in specimens examined nearly glabrous, possibly due to rubbing. 



Prosternal teeth 2-2, 3-3; when 3-3 the external tooth on each side 

 more widely separated from the median than the latter from the in- 

 ternal. 



Angles of the 9th, 11th, and 13th dorsal plates produced; 1st and 3d 

 scuta considerably sinuate posteriorly, 5th slightly so 7th straight, 

 8th, 10th and 12th sinuate. 



Spines of first legs ^j^;o' ^^ *^^® penult ^^^{, the claw with 1 spine; 

 of the anal qi's 30' ^^^^ ^^^^^ v^'Wh 1 spine. 



