TAXONOMIC STUDY OF MORDELLIDAE — RAY 309 



MORDELLISTENA CHIAPENSIS, new species 

 FiGUBE 18, n 



This species is most closely allied to gracilicornis Champion (1891, 

 p. 318) and may be separated from the latter member of the genus 

 by the distinct difference in color pattern of the dorsal surface, the 

 shorter, broader antennae, the broader, more rounded distal segment 

 of the maxillary palpi, and the longer anal style. 



Length: (male) 3.9 and (female) 4.9 mm.; including anal style, 

 (male) 4.9 and (female) 6 mm. Form elongate, narrow, sides sub- 

 parallel, distinctly narrowing at apical third of elytra, broadest at 

 middle of pronotum. Body brunneous, legs a little lighter, eyes, tips 

 of mandibles, and ridges of posterior tibiae and tarsi black. Surface 

 densely covered with fine, recumbent pubescence, distinctly yellowish 

 on entire body, except on posterior tibiae and tarsi and anal style, 

 where it partakes of ground color. 



Antennae (male) 1.4 o.nd (female) 1.7 mm. long, reaching base of 

 abdomen ; segment 4 distinctly longer but very little broader than 3 ; 

 5-10 somewhat flattened and a little dilated at apex, each as long as 

 and noticeably broader than 4; 11 one-third longer than 10, sides and 

 apex rounded, broadest at distal third. Distal segment of maxillary 

 palpi enlarged, strongly robust, with the form of an isosceles triangle, 

 mesal and apical sides equal in length, ail sides and corners distinctly 

 rounded, broadest medially. Eyes large, coarsely granulated, an- 

 terior margin emarginate (male) or truncate (female). Pronotum 

 but slightly broader than long (1.2 by 1 mm. in male, 1.5 by 1.3 mm. 

 in female), sides subparallel to within a third of apex, thence attenu- 

 ate and broadly rounded to apex, apices individually rounded. In- 

 termediate tibiae and tarsi equal in length; penultimate segment of 

 anterior and intermediate tarsi dilated, emarginate at apex, receiving 

 distal segment on its ventral surface. Posterior tibiae with four 

 subequal, oblique ridges extending halfway across outer surface ; basi- 

 tarsi with four, second segment with two oblique ridges, all extending 

 halfway across outer surface. Tarsal claws with five distinct teeth, 

 distal four long, acute, proximal one premedian, short, blunt, obtuse 

 (fig. 18, n). Outer spur of posterior tibiae less than twice as long as 

 inner one. Anal style distinctly more than twice as long as apical 

 ventral segment (1 by 0.4 mm. in male, broken in female), narrow, 

 attenuate to apex; last ventral segment twice length of penultimate 

 one. 



Type locality. — Finca Belen, Chiapas, Mexico. 



Type.— Male, U.S.N. M. No. 52944. 



Remarks. — Two specimens, type and allotype, were taken at Finca 

 Belen, Chiapas, Mexico, April 22, 1932, at light, 800 meters elevation 

 (A. Dampf). 



