l46 



THE ORDER OF COLEOPTERA. 



This family is co-extensive 

 with the tribe of sliort-horued 

 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 Curculionidte, 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 4SPIN0SUS, Say; S. CARY^, Eiley :— 1, shows the tt<„^. Q^^i^fT- nno liimrlr-orl QTi/1 



burrows of the larvae between the bark and the wood, -li'Ht- OOClCty, OUC nunOiea aUCl 



growing 

 eggs are ( 



are enu- 



ig wider as they diverge from the line where the ii,„„p -nt a <sr»ppip<« 



re deposited ; 2, another view of the same, showing ^^'■*-^*' -^ ' ■^^* opci^ico 



tiie hole made by the exit of the beetle; 3, beetle, both -„„„„j.p J Hicfrihnfprl in pi.tIi 



magnitied and natural size; 4, larva, the same; 5, pupa "^*'^'*'''^'^'^> UihlilUiiLt^U in ei»u- 



magniaed-afterKiiey. ^^^jj gcncra or sub-gcncra. 



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

 genera : 



A. Head free; 1st joint of the tarsi as long as the others united Platypus. 



A A. Head deeply inserted in thorax ; fiist 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 antennae sub-globular. 



E. Six joints in the antennte before the knob Hylurgus. 



E E. Seven joints in the antenna? before the knob Htlastes. 



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



C C. Head globular, invisible from above ; 3d joint of tarsi not bilobed ToMicus. 



B B. Venter turned up behind Scolytus. 



The Platypus coinpositus, 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. 



Sylurgus, 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 



