A NEW SPECIES IN THE CHILOPOD GENUS 
THE AT OPS 
By Ralph V. Chamberlin 
University of Utah 
The finding- of a new species of Theatops, making the 
fourth well defined species known in the genus, is of con- 
siderable interest. The type of the new form was taken 
in a cave in Sonora, Texas, and may be a definitely cavern- 
icolous species. The four species of the genus may be 
distinguished by means of the following key. 
Key to Species of Theatops 
1 (3) Prefemur of anal legs with no spine at mesodorsal 
corner 2 
2 Prefemur and femur of anal legs entirely lacking 
spines or teeth; coxopleurae not mesally elevated, 
with no spine; tibiae 1 to 9 with a single ventral 
spine. postica (Say) 
Prefemur and femur of anal legs each with one 
ventral spine; coxopleurae with inner border ele- 
vated and bearing caudally a spine or tooth; at 
least some of the tibiae 1 to 9 bearing a second 
spine . erythrocephala (Koch) 
3 (1) Prefemur of anal legs with a distinct distal spine 
at mesodorsal corner 4 
4 Last tergite with no median longitudinal sulcus; 
antennae and articles of normal length 
spinicauda (H. C. Wood) 
Last tergite with a sharply impressed median long- 
itudinal sulcus; antennae and its articles long 
and slender phanus, n. sp. 
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