372 



MEMOIRS ON THE COLEOPTERA 



pygidium (9) strongly convex but not protuberant posteriorly; 

 carinee of the last dorsal (cf ) long, strong and parallel; abdomen 

 much more finely punctured than in ocellata. Length (cf 9 ) 14.0- 

 17.0 mm.; width 3.1-3.7 mm. Pennsylvania (Franklin Co.), 

 West Virginia and North Carolina (Southern Pines), [phimbea 



Oliv.] ruficollis Fabr . 



Form shorter and relatively still broader, the disk of the elytra broadly 

 flat or slightly concave, the color very different, pale ochreo-fer- 

 ruginous throughout, the elytra each with a black vitta at the 

 summit of the flank, the tarsi and the tibiae except basally, black, 

 the antennae piceous-black basally; pubescence short, sparse and 

 very inconspicuous; head and prothorax with strong close punctures, 

 the latter not as long as wide (cf ) to distinctly wider ( 9 ), the parallel 

 sides but feebly and subevenly arcuate; vestiges of the callous spots, 

 two in number, very feeble; elytra rather short, only between three 

 and four times as long as wide, coarsely, serially punctate, the punc- 

 tures very deep, well separated and rounded, smaller and confused 

 apically and near the suture; exterior of the raised discal lines much 

 stronger and more nearly entire than in any other species; apices 

 obliquely truncate, scarcely at all bidenticulate; pygidium (9) 

 very moderately convex, not at all protuberant. Length (cf 9 ) 

 10.0-12.5 mm.; width 2.0-2.7 mm. North Carolina (Southern 

 Pines), Manee gracilis Fabr. 



The above study has had as its object the most practical arrange- 

 ment for the identification of the species; ruficollis, for example, is 

 really more closely related to guadricallosa than to any of the inter- 

 mediate forms of the table, the most evident difference being the 

 absence of black coloration on the four thoracic callous spots of the 

 former. In the difficult bimaculata group, I am unable to state just 

 which may ultimately prove to be true species, or designate at 

 present those that should hold a lesser rank; they cannot all be 

 subspecies of bimaculata, for some of them, such as insignis, dolosa 

 and exilis, have well marked distinctive structural peculiarities and 

 perspicillata has less filiform antennae; so I will leave them as an- 

 nounced until further light can be shed on the subject by means of 

 carefully collected material. 



The species in Oberea are variable in color, it is true, but they have 

 not the almost illimitable fortuitous variability that has been 

 ascribed to them by those who have not even taken the trouble to 

 separate the sexes and note the purely sexual divergencies of colora- 

 tion ; it is this apparently erratic variability that has chiefly served 

 to discourage nearly all investigation of the genus. I find that the 

 variability they possess has its limits, and that these are much less 



