DYNASTIN/E 247 



lines are obsolete and that there are some very small feeble sparse 

 pustules in addition to the minute punctulation; the punctures are 

 very small, closer, distinct and simple at the apical margin and the 

 sutural stria is evident only near the apex and even there fine, 

 irregular and not at all groove-like; marginal gutter curving inward 

 just behind the humeri; intra-humeral basal impression deep; 

 pygidium very short, almost four times as wide as long, otherwise 

 nearly similar; tarsi and the very conspicuous tibial spurs similar. 

 Length (cf) 30.0-34.0 mm.; width 17.5-19.0 mm. Florida. One 

 fully developed male and two in intermediate stage . . atrolucens n. sp. 



Upper surface castaneous, sometimes blackish but only in the female so 

 far as noted; anterior tibiae moderately stout and dentate; pygidium 

 less transverse, never quite three times as wide as long and some- 

 times much less, the upper margin, as in all the species except 

 mormon, broadly and feebly sinuate medially somewhat as in 

 Bothynus 5 



5 Female with the anterior thoracic concavity more or less shallow, 

 and smaller in size, scarcely ever extending so far posteriorly as the 

 middle of the pronotum. Male, when fully developed, a little less 

 stout than in the two preceding species, oblong, more elongate, 

 polished, the anterior parts a little darker than the elytra and some- 

 times nearly black; head small, less than a third as wide as the pro- 

 thorax, very coarsely rugose, the medial part of the clypeus with only 

 a few sparse and feeble lineiform rugae and some fine scattered 

 punctures; lateral parts of the apex smooth, finely, not densely 

 punctate, the apex broadly and obtusely rounded, not reflexed, with 

 a small obtuse nodule at the middle; front with a medial vortex in 

 the rugosity separating two very feeble, indefinite, irregularly 

 rugose tumidities; middle mandibular tooth as in atrolucens; mentum 

 rather smooth, with smaller sparse punctures medially; prothorax 

 nearly as in atrolucens throughout, but less transverse, scarcely 

 over one-half wider than long; apical horn similarly very long but 

 with the apex rather less strongly reflexed, the posterior horns more 

 broadly thickened gradually toward base; scutellum less transverse; 

 elytra longer, fully as long as wide, fully as wide as the prothorax 

 and nearly three-fourths longer, otherwise nearly similar but less 

 broadly rounded behind; pygidium not quite three times as wide as 

 long, convex and nearly similar to that of atrolucens, except that the 

 confused basal punctures are smaller and the erect hairs much 

 shorter and finer. Males in the less developed stages gradually 

 decrease in size, the apical horn of the prothorax becomes much 

 shorter and is finally but little more than a strongly elevated tubercle, 

 though always at least a little larger than in the female, the posterior 

 horns become very short, relatively broad and finally disappear 

 completely, but the pronotum is never in any marked degree similar 

 to that of the female, the concavity remaining relatively much larger; 

 in the successively diminishing stages the thoracic concavity becomes 

 more and more rugose and finally there remains barely a trace of the 

 dividing ridge. Female very different from the male, darker in color, 

 more broadly oblong and less convex, the head just visibly larger, less 



