252 COLEOPTERA OF NORTH AMERICA. 



They are elongate hairy insects, usually of metallic color, found 

 in large numbers on leaves of trees; the claws are cleft at tip. 



Sub-Tribe 3. — Sericilli (genuini). 



This sub-tribe is also represented in our fauna by a single 

 genus, Serica, of universal distribution. They are oblong, con- 

 vex insects, of a brown color, usually vk'ith iridescent reflections; 

 the elytra are indistinctly sulcate; the pygidium is sometimes 

 partly covered by the elytra. 



It is readily distinguished from all others of this sub-family by 

 the labruni being connate with the under surface of the clypeus, 

 and therefore indistinct. 



The fifth ventral segment and the propygidium are separated 

 by a distinct suture, and the spiracle is placed external to this 

 suture, half way between the anterior and posterior margin of 

 the ventral segment. The posterior coxte are flat, and broadly 

 dilated. 



Sub-Tribe 4. — Itlaci'odactyliiii. 



, Three species of Macrodactylus, distributed from the Atlantic 

 to Arizona, alone represent this group in our fauna ; they are 

 commonly known as rose-bugs, and are very destructive to roses 

 when in bloom. They are elongate, brownish insects, densely 

 covered with ochreous scales, so as to appear yellow; the tarsi 

 are very long; the claws long, slender, diverging, cleft at tip; 

 the fifth ventral segment and propygidium are connfite, forming 

 a solid ring, and the last spiracle is placed on the suture. The 

 labrum is not connate with the clypeus; the mentum is narrow, 

 and channelled; the anterior coxae are conical and prominent; 

 the ventral segments are not connate, and the legs are slender. 



Sub-Tribe 5. — Sericoidiiii. 



This sub-tribe, as defined by Lacordaire, differs from the others 

 having conical, prominent anterior coxae, by the labrum being 

 distinct, and the mentum not elongate and channelled, as in 

 Macrodactyli. A portion having chelate ungues has been sepa- 

 rated to form the sub-tribe Dichelonychini. 



The ligula is connate with the mentum, which is concave; the 

 labrum is short and emarginate; the mandibles not prominent; 

 the epistoma margined in front; the antenna 10-jointed, the 



