364 MEMOIRS ox THE COLEOPTERA 



spiniform angle, the apices thence anteriorly sinuate to the suture; 

 punctures not very coarse or close, distinctly sublinear in arrangement; 

 legs very slender, long, the femora not clavate, the basal joint of the hind 

 tarsi longer than the next two combined; abdomen with sutures two to 

 four deeper than the first. Length n.o mm.; width 2.5 mm. Isthmus 

 of Panama (Darien). 



From apicalis Thorns., this species differs very much in its uniform 

 black color, more slender form, longer apical spines of the elytra and 

 still more elongate and more slender antennae. 



Essostrutha fimbriolata Bates, is represented in my collection by 

 four examples from Guerrero, collected by Baron; the sexual 

 differences in coloration are very remarkable, the male being entirely 

 yellow above, excepting the four rounded pronotal spots; in the 

 female the size of the body is not quite so large, the pronotal spots 

 subunited longitudinally and extending to base and apex, and the 

 elytra are deep black in basal fourth and apical third. Another 

 male example, from Ecuador, is smaller and shorter, ochreous- 

 yellow, except the four pronotal spots, which however are not discal, 

 as in the male of fimbriolata, but attain the apical and basal 

 margins; it represents a distinct species. 



Oberea Muls. 



This holsubarctic genus contains a very large number of forms, 

 which, because of some color variability, have caused a good deal 

 of difference of opinion among systematists; but after studying 

 my material attentively, the conclusion is forced upon me that the 

 views of Dr. Horn are very conservative, while those of Dr. Hamilton 

 can be characterized by no other term than irrational. In the 

 following arrangement of the American species color is not made the 

 basis of named taxonomic forms, unless accompanied by structural 

 characters which can be recognizably described, including outline, 

 sculpture, pubescence, special modifications of the elytral tips or 

 in some sexual peculiarity. Six of the hitherto described forms 

 oculaticollis Say, affinis Harris, tibialis, flavipes and myops of Halde- 

 man and texana Horn are apparently missing in my material, which 

 is moderately extensive ; it may be arranged as follows : 



Pronotum pale in color, with four black callous spots disregarding the 



median line, which is frequently elevated medially 2 



Pronotum pale to black, with two black callous spots 5 



Pronotum without more obscurely colored callous spots 16 



