150 Annals Entomological Society of America [Vol. V, 
these in voracior being circular or broadly elliptic whereas in 
devorans they are larger and mostly strongly transverse. In 
some cases, however, it is difficult to separate the females, 
although the males are always very readily distinguished by the 
character of the hair clothing the anal segment dorsally, this 
in devorans being long and dense with nearly all the hairs 
uncinate distally whereas they are all straight in the other 
species. Devorans averages larger. It is relatively more 
slender and the width of the head as compared with that of 
the tenth plate is as 60:70 on an average whereas the average 
corresponding ratio in voracior 1s 60:65.5 
Lithobius voracior sp. nov. 
Dorsum brown, the first plate and the several most caudal ones 
commonly darker and more reddish of chestnut; plates often showing 
three longitudinal pale lines. Head conspicuously darker than the 
dorsum, cherry red or chestnut, or in others often very dark, nearly 
mahogany. Antenne chestnut, much lighter distad. Prosternum 
dark brown or dilute brownish chestnut, with the prehensors paler. 
Ventor yellowish brown, the posterior plates much darker, burnt 
brown. Legs yellowish brown, the posterior pairs darker, being often 
somewhat chestnut with distal articles a little paler. 
Head wider than long. Widest immediately back of eyes. Sides 
rather strongly convex and converging caudad of the well marked 
marginal breaks to the rounded posterior corners. Caudal margin 
nearly straight or but slightly incurved mesally. The usual subcircular 
impression on caudal portion. Surface subsparsely punctate, the 
puncte varying in size but mostly fine; obscurely uneven. 
First dorsal plate with surface similar to that of head. All finely 
punctate. Plates roughened more especially the caudal ones as usual, 
the elevations or irregular tubercles small. Posterior angles of seventh, 
ninth, eleventh and thirteenth dorsal plates strongly produced, processes 
of the seventh much as in devorans. 
Anal segment in male dorsally densely clothed with rather long and 
strictly straight hairs, these not being at all distally curved or uncinate. 
In the female the dorsal hairs of this segment are but sparse. 
Ventral plates densely punctate and with numerous fine impressed 
lines which mostly run out from the puncte. The usual longitudinal 
furrows clearly developed. Hairs of posterior plates more numerous 
and longer. 
Antennz of moderate length, reaching mostly to the end of the 
seventh or beginning of eighth segment. Attenuated considerably but 
the distal portion not very fine. Articles beyond the first several rather 
short. Hairs moderately long. Articles in number from 32 to 36. 
Eyes composed mostly of from 30 to 35 ocelli, rarely as few as 23, 
arranged in from 5 to 7 longitudinal series; e. g., 1+, 5, 5, 5, 4; 1+3, 4, 
5,'6,:°5, 4,:2* 1-55, 5, 6,6, 4,3; 1-23, 5, 6; 6,6, 4.35 -F 4G Oh ome 
