LEAP-CHAFERS. 87 



color and in the form of the thorax j but as these (jliaracters are varia- 

 ble ill both species, it would, perhaps, be more correct to regard them 

 Old}' as varieties. 



The g^enus rhyUophufia^ Harris, {Laclnwsferna, Hope,) is very numer- 

 ous in species, many of which, liowever, bear a close resemblance to 

 each other. It is emi)hatically, but not exclusively, a North American 

 <;enus, (!G of the IKJ known species bein*j' found in this country. Tlicy 

 ma> be divided into live groups, accoi«iiug to the dotliing of the body. 

 In the first and most numerous group, of which the common May-beetle, 

 /*. fusca, may be taken as the ty])e, the upper side is smooth and sinn- 

 ing. The second group contains but one species, the P. lanerolain. Say, 

 found mostly west of the INIississippi river, and remarkable for having 

 the body ch)thed with snnill lance-shaped cinereous scales. In the third 

 grjuip the body is more or less clothed above with soft erect hairs. 'J'wo 

 spec'ies of this grou]) are common in some localities, the P. hlrtindu, 

 Knoch, and the L. Georgicana, of Gyllenhal. In the former the hairs 

 on the elytra are an-anged mostly in three rows, whilst in the latter 

 they are eipially distributed. The fourth group contains a small num- 

 ber of large species, in which the whole upi)er surface is densely clothed 

 with short lu'ostrate hairs or down. The P. ilicis, Knoch, is the tyjx' of 

 this group. The (ifth group is composed of comparatively small si)e- 

 cies, about half an inch in length, of a pale color, partly smooth above, 

 but with the thorax and base of the elytra densely clothed with long 

 hairs. The P. tri.siis, Fab., the same as the P. pihsicolUs^ Knoch, the 

 type of this group, is not uncommon. One other species is found in 

 Texas. There is also a number of small ])ale s]>ecies, half an inch or 

 less in length, with the body glabrous, which might constitute a sixth 

 group. The P. loiigitarsis, Say, is the type of this group, remarkable, 

 as its name iniplies, for the length of the tarsi. 



Itnuistbe remarked that all the species of this genus are densely 

 hairy on the under side of the breast, as indicated by the generic term 

 Ijdihnosterna, of Hope. 



The common llose-bug, {M. s)(hs])iuo}ius, Fab.) is the tyj)e of the genus 

 Mdcnxldctylusy Latr., a word nuMiiing long tarsii.s. The Kose-bug is ix'- 

 tween three and a half and four-tenths of an inch in length, covered all 

 over with minute ochre-yellow scale like hairs, which are not distinctly 

 visible without the aid of a magnifter. The thorax is also somewhat 

 densely clothed with short upright hairs. A specimen fr<»m Georgia, 

 with the hairs more conspicuous, has been described by Dr. [jcC^onte 

 under the mime setiilosus. Another species, the angustatus, I'al. de 

 Beauv., found iu the Southern States, is distinguished l>y its longer 

 thorax, and the absence of the erect hairs. The genus is exclusively 



