24 PP.OCEEDTNGS OF THE NATIONAL MUSEUM. toi,.xxiv. 
sometimes possessing as many as small lobes or crenulations; basal 
spines 2 — 2, short, stout, usually widening upward to the middle and 
conical or pointed above. The head in the male is proportionately 
wider than in the female. The inner claw of the anal feet is also 
larger in the male, l)eing often indistinct in the female. Length of 
the body 12.2-13.8 mm.; width 1.8-2 nun.; length of the anal legs 
5-5.6 mm., mostly near the lesser limit. 
ITahitat. — With the preceding form over the foothills a])out Salt 
Lake City, but less al)undant. 
7}/7>.=.— U.S.N. M., No. 784. 
5- LITHOBIUS XANTI Wood. 
JTahitat. — Common along all mountain streams. This species and 
Litlu ihiam utahenx't X 'AXi^ the forms liy far most abundant in the canyons. 
6. LITHOBIUS FORFICATUS (Linnaeus). 
ITahitat. — In and aliout Salt Lake City, Avhere it is nuich the com- 
monest species, ]>ut not found in the mountains. 
The antenna' are most conunonly either 81! or Ht^ jointed. 
7. LITHOBIUS INTERMONTANUS, new species. 
Diagnosis. — Separated from other species previous I3' descrilied by 
the following points: Posterior coxae unarmed; articles of the antennt\3 
20; prosternal teeth 5 — 5; coxal pores B, 8, 8, 8, round; ocelli 10, in 
6 series; length 7.5-9 mm. 
Descripti(m. — Color, chestnut ])rown; antennae and legs paler. 
Antenna^, length 2.65-2.75 mm.; articles 20; sparsely hirsute at 
))ase, elsewhere nearly glabrous. Ocelli 10, arranged in 6 series in 
a linear patch. Prosternal teeth 5 — 5. Spines of the lirst legs 2, 3, 2. 
Last tarsal joints of the first pairs of legs more densely hirsute beneath 
than the inner ones. Posterior coxas unarmed. Coxal poi'es 3, 3, 3, 3, 
round. Length of the body 7.5-9 mm.; width 0.8-1 mm. 
llahitat. — Branch of Mill Creek Canyon. The eight specimens 
o])tained have all lost the posterior pairs of legs. 
ry/;t^.— U.S.N. M., No. 785. 
8. LITHOBIUS PURPUREUS, new species. 
Diagmms. — Anal feet each armed with two claws; articles of the 
antennae 28-32; spines of the first legs 0, 0, 1, of the last 1,3,8,0 or 
1, 3, 1, 0; coxal pores 2,3,3,2 — 3, 4, 4, 4; length 7-8.5 mm. 
Description. — Color, dark purple brown, the purple tint often con- 
spicuous and unmixed; head and legs yellowish brown, the tarsal 
joints of the last pairs of legs commonly lighter; antenna? dark, yel- 
low or rufous at ends. Antenn.e, length 2.3-8 mm.; articles, except 
