FIVE XFAV LTTnOBIW.F^-CHAMBERLIN. 23 
Anal legs of male, tibia swollen and excavated within near its anterior 
joint, at which it, together with the femur, is produced inward into a 
lobe which is often veiy conspicuous. Length of the body 7.5-11 
mm.; width 0.8-1.2 nmi. ; length of the anal legs 2.5-3 mm. 
Ilahitat. — Common along all mountain streams, loving particularly 
the damp beds of decaying leaves and vegetable loam. 
7///>r.— lT.S.N.M.,No. 782; collected in Netf's Canyon, Salt Lake 
County, Utah, July 15, 1900. 
3. LITHOBIUS COLLIUM, new species. 
DragnonH. — Joints of the antennae 20-23; ocelli 18-22, in 7 vertical 
series; spines of anal legs 1,3,2,0; claw of genital forceps wide, 
lobes short, the middle one not much longest. 
Description. — Color brown, head and dorsal plates with a tendency 
to red brown, which may be strong; antennje and legs yellow or light 
brown. Head smooth. AntennaB, length 1-5.5 mm.; articles 20-23, 
graduallv decreasing in length toward the end; pilose. Ocelli 18-22, 
in 7 nearly vertical series. Prosternal teeth 2 — 2, small. Spines of 
the first legs 1, 3, 2—2, 3, 2; penult 1, 3, 3, 2; anal 1, 3, 2, 0. Posterior 
coxse laterally armed. Coxal pores 3, 4, 4, 3 — 3. 4, 1, 4, small, round. 
Genital forceps, claw rather long, wide, tripartite, the lobes short 
and rounded, the middle one but little longer than the lateral, or the 
claw subentire; basal spines 2-2, moderate, the outer spine on each 
side somewhat stouter. Length of body 13-15.8 mm.; width 1.6-1.7 
mm. ; length of the anal legs 4-5 mm. 
Ilahitat. — Common over the foothills about Salt Lake City during 
the spring and autumn months. 
ryy><^— U.S.N.M.,No. 783. 
4. LITHOBIUS SOCIUS, new species. 
Diagnoi<l)<. — This species is to be separated by the following points: 
Coxal pores 4, 5, 5, 4 — 5, 6, 6, 5; articles of .,the antennje 20-25; spines 
of the anal legs always 1, 3, 2, 0; characters of genital forceps; and size, 
12.2-13.8 mm. 
Deso'lption. — Color, head and posterior dorsal plates brown; other 
dorsal plates mostly dark brown to brownish black; antennjv and legs 
yellow to light brown. Head smooth, wider than long. Antennae, 
length 5-5.7 mm., but mostly near the lesser limit; articles 20-25; 
first 7-12 joints long, others short; pilose. Ocelli 16-22, arranged in 
6-8 series. Prosternal teeth variable in size and number, <) — to 2 — 2 
and 3 — 3 (as connnon) or even to 5 — 5. Spines of the legs, first 1, 3, 2; 
penult 1, 3, 3, 2; last 1, 3, 2, 1. Posterior coxae laterally armed. 
Coxal pores 4,5,5,4 — 5,6,6,5; large, subcircular, or in part trans- 
verse, (xenital forceps, claw normally tripartite })ut by obliteration 
of the outer lol)e often bipartite or subentire, and on the other hand 
