AMERICAN COLEOPTERA. 



ReTision of the species of P©L,YPHY1.1.A of the United 



States. 



BY GEORGE H. HORN, M. D. 



The generic characters of Polyphj/lla have been so often given that 

 it is unnecessary to repeat them here. In the " Check List," Mr. Crotch 

 has separated our species from those of Europe under the name of 

 31acraiwxia, but no reason is apparent to me for such a course. 



The males are much more abundantly found than the females the 

 latter rarely flying, while the males are often seen circling in flight in 

 considerable numbers over the spot where the female may be. 



As the "males are the more abundant and as they present structural 

 characters by which they may be distinguished, the following table is 

 based on that sex alone. 

 Anterior tibiae tridentate. 



Body above distinctly scaly; clypeus trisinuate Hammondi. 



Elytra with scale-like hairs; clypeus truncate cavifroiis. 



Anterior tibise bidentate. 



Clypeus trisinuate, the lateral angles distinct. 



Head and thorax with moderately long erect hairs and very few scales. 



crinita. 



Head and thorax scaly with short hairs only decenilineata. 



Clypeus truncate or arcuate, the angles not prominent. 



Elytra distinctly vittate occidentalis. 



Elytra with irregularly placed denser spots variolosa. 



Anterior tibiae with the outer apical angle alone prolonged. (That of the female 

 bidentate) gracilis. 



P. Hammoudi Lee, Journ. Acad. 1856, p. 228; subvittata Lee. loc. cit. 

 p. 229.-Clvpeus trisinuate, the lateral angles prominent, vertex with short erect 

 hairs. Thorax with few erect hairs in front, surface very sparsely scaly and with 

 three denser vittte, the median more distinct; hind angles either distinctly rect- 

 angular or obtuse. Elvtra very sparsely scaly, the scales in indistinct vittse, the 

 sutural more dense. Bodv beneath clothed with moderately long fine yellowish 

 hair, abdomen sparsely scaly, scales denser along the posterior borders of the 

 segments. Length .96—1.16 inch; 24—29 mm. 



Jfa/e.-Antennal club 7-lamellate, arcuate or sigmoid, more than twice as long 

 as the stem. Anterior tibiae tridentate, middle tibia, bispinous on the outer edge, 

 posterior tibise with two short oblique ridges. 



Fema/e. -Angles of clypeus not prominent. Antennae short, the club not more 

 than half the length of the stem, composed of fine joints forming a rather compact 

 mass, the contiguous joint of the stem half as much prolonged as those ot the .club. 

 Tibial characters as in the %. 



The form subvlffnfa differs only in having the elytral vittae a little 



better marked. 



(14\ JUNE, 1881. 



TTtANS. AM. ENT. SOC. IX. I,1-*J ' 



