120 DESCRIPTIONS OF NEW SPECIES. 



necting the labrura with the epistoma ; in the female the epistotna 

 is truncate, and the connecting membrane is invisible.* 



394. Rb. gracilis. Elongatus ater subnitidus, capite elongato, pune- 

 tulato, thorace laevi, latitudine vix breviore, antice fere truncato, lateribus 

 rotundatis tenuiter ruarginatis, basi bisinuata, medio marginata, angulis 

 anticis deflexis haud proniinulis, posticis rectis retrorsum prominulis ; 

 elytris elougato-ovalibus, convexis, thorace duplo latioribus, basi sub- 

 emarginati-i, hu trier is subrotundatis, dorso striis utrinque 8 marginalique 

 punctulatis, parum iinpressis ; stria scutellari brevi fere obsoleta. Loug. 

 •72— -75. 



Cape San Lucas, Lower California ; Mr. Xantus. The thorax 

 is dull, impunctured, nearly truncate in front, with the apical 

 angles not prominent, the sides are rounded, aud widened to a 

 little distance behind the middle, then narrowed to the base, 

 which is slightly sinuate near the hind angles: these are rectangu- 

 lar and somewhat prominent : the base is finely margined by a 

 slightly curved line extending to within a short distance of the 

 hind angles, and in front of this line a slight transverse elevation 

 is seen, anterior to which is a very vague transverse impression. 



In the male the antennas are longer than the head and thorax ; 

 but in the female they are a little shorter and more thickened 

 externally. 



XYLOPINHS Leg. 



395. X. aenescens. Piceo-aeneus nitidus, capite thoraceque sat dense 

 minus fortiter punctatis, hoc latitudine breviore parum convexo, apice 

 late emarginato, lateribus late rotundatis, tenuiter marginatis, basi trun- 

 cata marginata utrinque foveata, angulis anticis rotundatis, posticis 

 rectis, ante basin transversim impresso ; elytris thorace latioribus, paral- 

 lelis, convexis, striis impressis punctulatis, interstitiis planis, parce sub- 

 tiliter punctulatis ; antennis pedibusque concoloribus. Long. # 50 — *57. 



Mas, tibiis anticis ad medium latere interno obtuse dentatis, dein usque 

 ad apicem late emarginatis ; tarsis anticis et intermediis articulis 1-3 

 paulo dilatatis, subtus spongiosis. 



Femina, tibiis anticis, tarsisque anterioribns simplicibus. 



Middle and Western States. Quite distinct from X. saper- 

 doides by the brassy lustre, the broader thorax, and by the trans- 



* Lacordaire (Gen. Col. V, 377) mentions sexual differences in the form 

 of the epistoma in certain species of Zophobas, which seem to be of a 

 similar nature ; but I do not know whether the basal membrane becomes 

 visible wheu the euiarginatiou is deep. 



