
476 THE AMERICAN NATURALIST. [VoL. XXXVI. 
Pleure of last segment not much inflated, with about nine small pores 
on each side, these arranged along a suboval line on ventral and lateral 
surfaces ; last ventral plate narrow, the sides straight and parallel; anal 
pores small. 
Pairs of legs of male 45, of female 47—49. Length of male 19-21 mm., 
width .5—.6 mm. ; length of female 30-31 mm., width .9—1 mm. 
Adolescens. — Specimens 13 mm. long measure .4 mm. in width ; length 
of antenna 1.2 mm.; pleural pores four or five on each side; color pale 
yellow. 
Habitat. — Canyons near Salt Lake City, mostly among decaying leaves 
and in vegetable mo 
The types were sdti in City Creek Canyon, April 1, 1901. 
Geophilus atopus sp. nov. 
Description. — Rather slender, very gradually attenuated cephalad, 
more strongly caudad, depth of the body in the middle region as great as 
e width; head sparsely pilose, smooth, the basal plate and exposed dorsal 
partió ót prosternum more densely covered with hair, the dorsal scuta . 
mostly very sparsely clothed with short hairs, not at all roughened ; cephalad 
light brown, head a little darker at sides, caudad yellowish, antennze and 
legs concolorous with adjacent parts of bod 
Antenne short (2 mm.) ; the first three or four joints sparsely pilose with 
moderate straight hairs, the others more closely clothed with short hairs 
which increase in density to ultimate joint; ultimate article nearly equal in 
length to the two preceding taken together. 
Cephalic plate much longer than wide (5:4 nearly); anterior and pos- 
terior margins truncate; with two distinct lateral sulci and a fine discon- 
tinuous median line; frontal border of basal plate concealed, exposed 
portion thrice wider than long. 
Claws of the prehensorial feet when closed reaching to the middle of the 
first antennal article; claw armed at base with a pale obtuse tooth ; coxa 
armed similarly to claw; prosternum wider than long (9:8 approximately), 
less than twice the height of the coxa, anterior margin with only a shallow 
sinus, unarmed. 
Dorsal scuta with two rather faint lateral sulci and a single median 
sulcus, these more strongly impressed caudad ; first dorsal præscuta short, 
irregularly increasing in length to the pne region, where they are long 
excepting the last few, which are v 
The first anterior spiracle subround, those following round, gradually 
decreasing in size caudad, finally becoming small or very small. 
Ventral scuta faintly sulcate, the anterior ones with a median depressed 
area Leve) on the plate; ventral pores large, arranged over and about 
the ressed area, extending forwards and backwards along the median 
s= add iiaae to ~ sides, farther caudad the pores mostly restri 


