chambeklin: chilopods from Mexico and west indies. o2o 



Lestophilus didymus, sp. nov. 



Dorsum \'ellowish, pale ochraceous anteriorly. Head darker, of a 

 dilute chestnut cast. Legs yellow, the antennae a little darker. 

 Prosternum and prehensors dilute chestnut. Venter yellow. 



Body conspicuously narrowed caudad but as usual only slightly 

 narrowed cephalad. 



Head anteriorly subsemicircularly rounded but anterior corners 

 somewhat angular. Narrowed from frontal region caudad, caudally 

 abruptly rounding in mesocaudad with a very short caudal part having 

 sides again subparallel. Caudal margin straight. 1.45+ times longer 

 than wide. Basal plate 2.6— times wider than long; as long mesally 

 as at sides; its width anteriorly equalling the width of the narrowed 

 caudal division of the cephalic plate. 



Antennae short and proportionately thick; 2.2 times longer than 

 the head plate. Ultimate article distally conically rounded, about 

 equal in length to the two preceding articles taken together. 



Claws of prehensors when closed extending a little beyond distal 

 end of the first antennal article. Claw armed at base with a conical 

 subacute black tooth. Femuroid with a paler, distally rounded stout 

 process or tooth of usual type and a small, rather vague protuberance 

 proximad of this. 



Prosternum with two small, Well-chitinized conical teeth close 

 together, one at each edge of the narrow, shallow median sinus. 

 Prosternum a little widest across anterior end. Exposed portion 

 wider than long in ratio 47: 43; 1.65 times longer than greatest length 

 of femuroid. 



Anterior prescuta very short; the others gradually increasing in 

 length toward the caudal end where they are of moderate size. Each 

 prescutum with a single transverse row of short straight hairs, each 

 scutum having a transverse row of fewer similar hairs across caudal 

 border and another one across the anterior border. 



Spiracles all circular. The anterior one much the largest with the sec- 

 ond intermediate in size, the others decreasing caudad, mostly small. 



Sternites with the usual median longitudinal sulcus which is deep- 

 est at or a little caudad of its middle where crossed by a weaker and 

 often indistinct transverse impression. 



Ventral pores few; as usual in a narrow transverse band in front of 

 the caudal margin. 



Coxopleurae of last pediferous segment moderate in size. Pores 

 small, numerous, not dense; occurring above and below, but above 

 confined to proximal end where in part covered as usual. 



Anal legs much longer than the penult; slender; clawless as always. 

 Bristles sparse, moderate, chiefly at distal ends of articles. 



