248 COLKOPTERA OF NORTH AMERICA. 



families are of a negative character; the posterior spiracles do 

 not diverge strongly, as iu the Fleurosticti ; the middle coxae are 

 not oblique, as iu the Luparosticti (except Trogiui), nor rounded 

 and separated from the side pieces, as in that tribe. There is also 

 a considerable ditference iu the adaptation of the last abdominal 

 segments. In Mclolonthiuse the fifth ventral is most frequently 

 connate with the penultimate dorsal, and the sixth segment, 

 usually visible, is rendered so merely by its size and firm con- 

 sistence causing it to be pushed out into view. Even when the 

 fifth ventral is not connate with the dorsal segment, they form 

 together a regular ring. 



In the preceding sub-family the sixth ventral segment is nor- 

 mally visible, although sometimes of small size and retracted; in 

 this case the pygidium or last dorsal segment is covered by the 

 elytra, and in a manner lies upon the fifth ventral ; the fifth 

 ventral is never connate with the penultimate dorsal, and does 

 not form with it a regular ring. 



In the first tribe of Melolonthinas (Glaphyrini) the sixth ventral 

 is quite visible, and the fifth is not connate with the penultimate 

 dorsal, but still they are adapted together so as to form a regular 

 ring, to which is articulated the protuberance formed by the pygi- 

 dium and sixth ventral, in the same position as in Melolonthina? 

 of other tribes in which the sixth ventral segment is external. 



According to the position of the abdominal spiracles, the tribes 

 of this sub-family divide into two sets. 



A. Laparostict Melolonthin^. 



Two tribes form in this division, and only differ from the tribes 

 of the preceding sub-family by individual peculiarities of moment, 

 though by no general character. 

 Mandibles and labrum prominent ; ventral segments six, free. 



Glaphyrini. 

 Mandibles and labrum beneath the clypeus ; ventral segments connate. 



Oncerini. 

 Tribe I.— GI.APHYRI]VI. 



Oblong, not convex insects, frequenting flowers, and remarkable 

 for the long hairs of the legs and under surface; the head and 

 thorax are also usually densely covered with long hair. The 

 elytra are flat, frequently dehiscent, and do not cover the pygi- 

 dium; the abdominal spiracles are all situated in the connecting 

 membrane ; the fifth ventral joins the propygidium, to form a 



