1 88 Annals Entomological Society of America [Vol.11, 



coming rufous; legs brown, distal joints paler; ventral plates brown, 

 uniform; presternum reddish brown. 



The body conspicuously narrowing from the tenth dorsal plate 

 forward. 



None of the dorsal plates truly produced, with the angles of the 

 eleventh and thirteenth but weakly extended. 



Antennae short; articles twenty-one, these gradually decreasing 

 in length from the base to the distal one. 



Ocelli on each side ten, arranged in three series (l-t-4, 3, 2.) 



Presternal teeth 2-2. 



Coxae of last three pairs of legs armed above, those of the last two 

 pairs also laterally. Anal legs with the claw unarmed, spines 1, 3, 3, 1. 

 Penult legs have the claw armed with two spines of which the anterior 

 one is sub-ventral in position and easily overlooked; spines 1, 3, 3, 2. 

 Spines of the first legs 1, 3, 2. 



Coxal pores round, moderate in size, 3, 4, 4, 3. 



Anal legs of the male a little crassate but less so than the penult. 

 The penult legs have the first tarsal segment strongly inflated and 

 bearing above at the distal end a conspicuous, short, keel shaped 

 process. 



Length 15.4 mm. Width of tenth plate 2 mm. Length of 

 antennae 3.G mm. anal legs short. 



Locality — Pullman, Washington (Mann) . 



The types consist of several males. 



34. Lithobius tivius sp. nov. 



Dorsum brown, the posterior margins of some scuta bordered with 

 a somewhat obscure, transverse dark band; head yell )wish or 3'ellow- 

 brown, often of a reddish tinge; antennae dark over the basal portion, 

 becoming lighter distally, rufous apically; legs yell wish brown, the 

 posterior pairs darker; venter paler than dorsum, its posterior plates 

 and also the presternum of rufous caste. 



Angles of none of the dorsal plates produced. 



Antennae short; articles thirty -one or thirty-two, the first two 

 articles long, the others, excepting the ultimate, very short. 



Ocelli on each side seven or eight, arranged in two series (1-|- 3, 3 or 

 1 + 4, 3). 



Presternal teeth 2-2, moderately large and distinct, darkened. 



None of the posterior coxae armed laterally or dorsally. Claw of 

 each anal leg armed with a single spine; spines 1, 3, 2, 0; moderately 

 crassate. Penult legs with the claw armed with two spines; spines 

 1, 3, 3, 0. Spines of the first legs 0, 1, 1. 



Claw of the female gonopods trilobed, the lobes mostly short and 

 obtuse, the outside one distinctly smallest; basal spines 2-2, short 

 and stout. 



Length 8 mm. Length of antennae 2.2 mm. Anal legs short. 



Locality — Pullman, Washington, and Salt Lake City and 

 Provo, Utah. 



