CHAMBERLIN: CHILOPODS FROM MEXICO AND WEST INDIES. 339 
distad of the third short and very short, varying irregularly in length, 
closely united. Ultimate article rather slender, as long as the two 
preceding articles taken together. 
Ocelli mostly 1+ 1, 3, 3. Single ocellus vertically subelliptic, of 
almost same size as first one of top series, these two being conspicuously 
larger than the remaining ocelli. Ocelli distinct and regular, often 
not contiguous with each other. Organ of Témésoary in outline of 
about same size as an average seriate ocellus. . 
Prosternum 1.48— times wider than long. Distance between 
chitinous spots 2.3 times width at level of bottom of sinus; 3.9 times 
the dental line. Prosternal teeth 2+ 2; line of apices a little re- 
curved. Sinus between V- and U-shaped. Spine bristle like, in- 
serted a little ectad of outer tooth on same level. Margin extending 
abruptly ectocaudad from spine. 
First dorsal plate in the type 1.53 times wider than long; sides only 
moderately converging caudad; caudal corners widely rounded. 
Posterior angles of ninth, eleventh, and thirteenth dorsal plates pro- 
duced. 
Coxal pores small; mostly 3, 3, 3, 3. 
Anal legs of male with the tibial process small, low and incon- 
spicuous. 
. 0,0,2,1,1. 0, 0, 2,2, 1, 
Spines of first legs, Ok ae of the second, 5-57-31: of the third, 
0,0, 2, 2,1. 
0, 0, 2, 2,2, 0,0,25.25.2" ae 
o01,22 % the fourth, 557-5; of the fifth, 55-55-53 of the sixth to 
602,22. 
0, 0, 3, 22, 
ninth, 9-95-3-9) Of the tenth and eleventh, 5 5->°3-5; © 
i,.0, 3, 2,2 
Pertecen,, 5-45; of the penult see 
? 0,1,3,3, 
1, 0, 3, 1, 0 . 
obsolescent; of the anal ;'=3-5-;, claws 2 or also a minute ectal acces- 
sory claw sometimes evident. No lateral spines on any of the coxae. 
Length 10-12 mm. 
f the twelfth and 
the ectal accessory claw 
Locatiry.— Mexico: Hidalgo, Guerrero Mills (W. M. Mann). 
Type, M. C. Z. 1741; six males, Type and Paratypes, M. C. Z. 1753. 
MEXICOBIUS, gen. nov. 
Head with marginal breaks present but small. 
Antennae very short; articles thirty-five or above. 
Eyes consisting of seriate ocelli. Single ocellus clearly differentiated. 
Prosternal teeth 2+ 2, small and nodular. Anterior edge of 
prosternum well chitinized, wholly without true sinus. Spines large 
and stout, much exceeding the teeth in size. 
Posterior angles of ninth, eleventh, and thirteenth dorsal plates 
