Leap-chafers. 87 



color aud iu the form of the thorax ; but as these characters are varia- 

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

 only as varieties. 



The genus PIiyllo;phaga, Harris, {Lachnosterna, Hope,) is very numer- 

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

 each other. It is emphatically, but not exclusively, a North American 

 genus, C)6 of the IIG known species being found in this country. They 

 may be divided into five groups, according to the clothing of the body. 

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

 P. fmca, may be taken as the type, the upper side is smooth and shin- 

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

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

 the body clothed with small lance-shaped cinereous scales. In the third 

 gioup the body is more or less clothed above with soft erect hairs. Two 

 species of this group are common in some localities, the P. hirtici(hf, 

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

 on the elytra are arranged mostly in three rows, whilst in the latter 

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

 ber of large species, in which the whole upper surface is densely clothed 

 with short prostrate hairs or down. The P. ilicis, Knoch, is the type of 

 this group. The fifth group is composed of comparatively small spe- 

 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. tristis, Fab., the same as the P. pilosivoUis, Knoch, the 

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

 Texas. There is also a number of small pale species, half an inch or 

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

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

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



It must be remarked that all the species of this genus are densely 

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

 Laehnosterna, of Hope. 



The common Rose-bug, {M. subspinosus, Fab.) is the type of the genus 

 Macrodactylus, Latr., a word meaning long tarsus. The Rose-bug is be- 

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

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

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

 densely clothed with short upright hairs. A specimen from Georgia, 

 with the hairs more conspicuous, has been described by Dr. LeConte 

 under the name setulosus. Another species, the angustatus, Pal. de 

 Beauv., found in the Southern States, is distinguished by its longer 

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



