cil^mberlin: chilopods from Mexico and west indies. 539 



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 Tomosoary 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 httle 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. 



Spines of first legs, q' "' ^' '^' | ; of the second, "' °' / 2' p ^^ ^^^^ third, 

 Q^yy—; of the fourth, q'^'^'^'^ ; of the fifth, ^^yy^l' ^^ ^^^^ sixth to 

 ninth, q\'7 s'l 'y ^f the tenth and eleventh, ^'^'^'g'^ ; of the twelfth and 

 thirteenth, ^+3*3'^ ; of the penult, ^ ^' 3' 3' ^ the ectal accessory claw 

 obsolescent; of the anal q' ^ 3' I' ^ , claws 2 or also a minute ectal acces- 

 sory claw sometimes evident. No lateral spines on any of the coxae. 



Length 10-12 mm. 



Locality. — 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 



