146 



(THE ORDER OF COLEOiPTERA. 



[^ig- '^1-J This family is co-extensive 



with the tribe of short-horned 

 borers which we have just de- 

 scribed. They are usually re- 

 garded as closely allied to the 

 Curculionidse ; but, as we have 

 stated above, they differ great- 

 ly from the latter in their food- 

 habits, and also in the details 

 of their organization. In ad- 

 dition to the characters given 

 above, we may add that they 

 differ from the great majority 

 of the tetramerous beetles, in- 

 cluding the Curculionidiie, in 

 having simple tarsi, not spongy 

 beneath, and with the last joint 

 but one not at all, or but very 

 T slightly, bilobed. In Dr. Le- 

 Conte's sketch of this family in 

 the 2d Vol. of Trans, of Am. 



ScoLYTus 4-sriNOsus, Say ; S. caryj5, Riley :— 1, shows the t^ ±. Cinpiptv nnp hnndrpd and 

 burrows of the larvfE between the bark and the wood, -'^'J^' f^OCiet^ , OUe UllUUieu dUU 

 growins wider as they diverge from the line where the j.i,„o„ ■vr a crkOi>i<ic nvA Ann 

 eggsaredepo8ited;2, another view of the same, showing ^^^^^'^ ^' '^' oP*^l.ie» die ciiu 

 the hole made by the exit of the beetle; 3, beetle, both .^r.QT'citQrJ rl i of rn Knforl in f>io-h 

 magnitied and iatnral size; 4, larva, the same; 5, pupa "^^^'*'^*^'-*^J UlSUlULUeu lU iii^u 



maguitied-after Kiiey. ^^^^ genera or sub-gcnera. 



But all the more common species may be included in the six following 

 genera : 



A. Head free; Ist joint of the tarsi as long as the others united Platypus. 



A A. Head deeply inserted in thorax ; first joint of tarsi much shorter than the others united. 

 B. Abdomen of the usual form. 

 C. Head not globular, visible from above; 3d joint of the tarsi slightly bilobed. 

 D. Knob of the antennas sub-globular. 



E. Six joints in the antennae before the knob Htlurgus. 



E E. Seven joints in the antennae before the knob Hylastes. 



D D. Knob of the antennae as long as the preceding joints united Hylesinus. 



C C. Head globular, invisible from above ; 3d joint of tarsi not bUobed Tomcus. 



B B. Venter turned up behind Scolytu8 . 



The Platypus compositus, Say, may be taken as a type of this genus in 

 this country. It is one-fifth of an inch long, of a reddish-brown color, 

 and each elytron has a three-toothed elongation at its extremity. Dr. 

 Chapuis, in his monograph of this genus, describes nine N. American 

 species, none of which are very common. 



Hylurgus, Latreille, contains a number of well known species, the 

 largest and most common of which is the H. terebrans, Oliv., of a reddish- 

 brown color, with the thorax deeply punctured, and quarter of an inch 

 in length. This insect is often seriously injurious to pine trees. An 



