44 



GG Elytral bases at most but moderately arcuate and not 



regularly serrulate; 1st and 5th ventral segments 



subequal in length and longer than the others 



(PL 9, fig. 26) ; the ligula slender, from a box-like, 



strongly chitinized basal inflation; the venter of the 



abdomen horizontal, (PL 9, fig. 42). 



H 3rd tarsal segment much widened and bilobed 



(PL 9, fig. 5); mesosternum protuberant in 



front (PL 9, fig. 35); bases of elytra usually 



rounded (PL 9, fig. 31.). 



Hylurgops Lee. Page 80. 



HH 3rd tarsal segment but little widened and emar- 

 ginate (PL 9, fig. 18); mesosternum not protu- 

 berant; base of elytra nearly straight. 



Hylastes Er. Page 77 . 



THE SUBFAMILY MICRACIN^E. 

 KEY TO THE GENERA. 



A The antennal club 5-segmented; abdominal segments 1 and 2 each about as 

 long as 3 and 4 together; the pronotum with an elevated area projecting 

 beyond the base of the thorax as a median lobe. In Cereus giganteus, 

 Arizona. C. hubbardi Sz. Cactopinus Sz. 



AA The antennal club 6-segmented; abdominal segments 1 and 2 each as long 



as 3, 4, and 5 together; the pronotum normal. 



B The elytra acuminate at the apex; the antennal club distinctly annulated 

 on both sides. Micracis Lee. Page 83 . 



BB The elytra not acuminate at the apex; the club not distinctly annulated 



on the inner side. Thysanoes Lee. Page 82 . 



This subfamily is apparently represented from Canada by only the three 



specimens of (Cryphalus) rigidus Lee. in the Leconte collection, although several 



species of Micracis occur in the northeastern United States, in twigs of various 



deciduous trees. 



THE SUBFAMILY IPIN^E. 

 KEY TO THE GENERA. 



A The eyes divided (PL 9, fig. 22); the antennal club without distinct 



sutures; metepisternum rather wide (PL 9, fig. 21). 



B The antennal club with the corneous basal segment broadly arcuate in 

 front (PL 10, fig. 11); the metepisternum narrowed and sinuate in 

 front, the sides parallel behind (PL 9, fig. 19) ; the male smaller than 

 the female, with the front convex. 



Xyloterinus, new genus. Page 83. 



BB The antennal club with the corneous basal segment strongly angulate 

 in front and produced towards the middle (PL 10, fig. 18) ; the met- 

 episternum strongly sinuate behind on the inner side (PL 9, fig. 21); 

 the male with the front deeply excavated, the sexes subequal in size. 



Trypodendron Stephens. Page 84. 

 A A The eyes not divided; the club with sutures at least at the tip. 



