AMERICAN COLEOPTERA. 45 



arcuate, surface sparsely punctured and pubescent, the pubescence so arranged 

 as to appear to form a denser space on each side of the middle and at the sides. 

 Elytra black, epipleurae pale, very sparsely cinereo-pubescent, surface sparsely 

 and irregularly punctured, punctures finer toward the tip. Tip feebly eniar- 

 ginate at the sutural angle % or obliquely truncate 9- Length .50 inch ; 

 12.5 mm. 



I have seen four specimens from Texas and others from Mexico 

 which vary among themselves in the color of the legs in some black, 

 others piceous and two entirely rufous. 



The sexual characters of Mecas are similar to Oberea, the last 

 ventral of the male is triangularly concave and the pygidium of the 

 female rather protuberant. 



OBEREA Muls. 



All our species have the middle tibiae sinuate on the outer edge. 

 The males have the last ventral segment concave and broadly emar- 

 ginate at tip. There is also an additional dorsal segment. The females 

 have the last ventral longitudinally impressed and feebly emarginate; 

 the pygidium is convex, sometimes protuberant in an obtusely conical 

 manner. 



The species from their variability of color are difficult to define, 

 the following table will however assist in their determination and 

 although founded on color characters it attains the object in view as 

 nearly as can be done. 



Body beneath and legs, black. 



Thorax entirely black OCUlaticollis Say. 



Thorax in great part yellow biniaciilata Oliv. 



Body beneath and legs variable, never both at the same time black. 



Thorax with four distinct callosities, pygidium of [ quadricallosa Lee. 



female strongly protuberant t Scliauniii Lee. 



Thorax with two or no callosities. Pygidium J feebly protuberant. 



Body beneath and above entirely black. 



Form moderately robust, middle and posterior legs black, anterior femora 



at apex and tibiae yellow. Thorax without callosities. ..tibialis Hald. 



Form very slender. Thorax with two callosities. Legs entirely yellow. 



flavipes Hald. 



Body beneath and above yellow or bicolored. 



Thorax with callosities. 



Elytra unicolored. 



Elytra slightly sinuate at tip, epiiileurte black; abdomen entirely 



rufous ocellata Hald. 



Elytra emarginate at tip and sub-bidentate, epipleurte pale at base; 



abdomen tij)ped with black texaiia n. sp. 



Elytra yellow with black stripes tripuiictata Swed. 



mi •., i ,, • • ( ruficollis Fab. 



Thorax without callosities i ... „ , 



I gracilis Fab. 



