CHAMBERLIN: CHILOPODS FROM MEXICO AND WEST INDIES. 501 
Locatity.— Mexico: Hidalgo, Guerrero Mill (W. M. Mann). 
TYPE, M. C. Z. 1758; ten specimens, several of which are immature, 
Type and M. C. Z. 1719. 
This species is closest to N. spinipes Pocock. It differs clearly in 
having all tarsi biarticulate; in having the anterior legs with but 
one tarsal spine additional to the ordinary dorsal one; in the number 
and disposition of spinules on the anterior legs; in the form and pro- 
portions of the first tarsal joint, and in the number of segments of the 
distal division of the anal legs (only 5-8 as against 13-14 in spinipes); 
in the very much smaller size. 
CRYPTOPS MANNI, sp. nov. 
Body yellow, with the head and caudal end a little darker. 
Head subcordate; strongly narrowed cephalad from the middle; 
caudal margin between rounded corners straight. Clearly longer 
than wide (ratio about 39:35). Smooth. No sulci evident. 
Prosternum with paired submedian longitudinal sulci which are 
not sharply defined. Not punctate. Anterior margin nearly straight 
except at ends where rounded caudad, also slightly indented at 
middle; on each side of middle bearing a pair of bristles directed 
cephalad and on each lateral curved portion another pair directed 
ectocephalad. 
First dorsal plate with anterior border overlapped by the cephalic 
plate. A distinct transverse semicircular sulcus close to the margin 
of head, the sulcus not at all angulate at middle. Longitudinal sulci 
faint. Plates from the second caudad longitudinally bisulcate, the 
caudal ones especially showing in addition a curved sulcus on each 
side which is deepest on the cephalic part of plate. Plates not rough- 
ened or bearing cornicles. Hairs sparse. Last tergite with caudal 
margin mesally strongly convexly protruding; with a median longi- 
tudinal suleus which is not distinct anteriorly; no pit-like depression 
caudad. 
Last ventral plate with sides nearly straight, converging caudad. 
Caudal margin a little incurved or indented mesally. 
Coxopleurae not at all produced caudally. Pores few. 
First pairs of legs with tarsi entire but a division appearing and 
becoming more and more clearly detectable in proceeding caudad. 
Prefemur of anal legs bearing numerous moderately stout spines 
ventro-laterally with longer bristles intermixed, a longitudinal ventral 
area free from spines but bearing bristles; dorsally at the distal end 
the joint is longitudinally furrowed and bears on the mesal side a 
stout short spine. Femur ventrally also with numerous long spines; 
