26 BULLETIN 46, UNITED STATES NATIONAL MUSEUM. 



An term ae short, joints 20-31, rather short and thick; densely pilose. 



Ocelli distinct, 9-10, in 4-6 series. 



Prosternal teeth 4, small and indistinct. 



Coxal pores 2, 2, 3, 2-2, 4, 3, 2, round. 



Spines of the first pair of feet, 2, 3, 2; penultimate 1, 3, 3, 1 ; last pair 

 1, 3, 3, 1-1, 3, 3, 2. 



Posterior pair of feet moderate, not swollen. Claw of the female 

 genitalia wide, tripartite, the middle lobe not much longer; spines short 

 and robust, the inner shortest. 



Length of body 6-9 mm ; last pair of legs 2-2.5 mm . 



Habitat. — Bloomington, Ind. 



This species is common; I have taken it mostly under boards laid on 

 a heavy growth of grass in the spring. 



Subgenus Lithobius Stuxberg. 



9. Lithobius howei, sp. nov. 



Brown; head chestnut, antennae very dark, feet and ventral laminae 

 pale. 



Eobust, not smooth, more so posteriorly; sparsely pilose. 



Head large, subquadrate, a little wider than long; sparsely pilose. 



Antennae short, joints 20, mostly long; densely pilose. 



Ocelli distinct, 25, arranged in 7, very oblique series. 



Prosternal teeth 6, small. 



Coxal pores 5, 5, 6, 5, large and oval. 



Spines of the first pair of feet 2, 3, 2; penultimate lost; last pair 

 1, 3, 3, 1. 



Last pair of feet rather long. ♦ 



Length of body 15 mm ; last pair of legs 7 mm . 



Habitat— Fort Snelling, Minn. (Walter D. Howe.) 



This species is described from one male in a rather bad condition, 

 collected by my friend and fellow-student Mr. Walter D. Howe, after 

 whom the species is named. 



10. Lithobius ? aztecus Humbert & Saussure. 



Lithobius aztecus Humbert & Saussure, Eev. & Mag. Zool., 2 e ser., xxi, 156, 

 1869. 



Brown; scuta margined posteriorly with dark; head and antennae 

 dark; prehensorial feet and tip of antennae rufous; feet and ventral 

 laminae very pale. 



Bobust, not smooth, more so posteriorly; sparsely pilose. 



Head large, subquadrate, a little wider than long (4.5 : 4) ; nearly 

 smooth, sparsely punctate; a few hairs scattered over the surface. 



Antennae moderate, joints 31, rather densely pilose. 



Ocelli 27, arranged in 8 series, rather crowded together. 



Prosternal teeth 12, the inuer very small, the rest of an even size. 



Coxal pores 7, 7, 6, 5, round and small. 



