NORTH AMERICAN BOSTRICHIDAE 101 



female external characters. The male sometimes differs from the 

 normal male in not having the horns on the pronotum, the horns being 

 replaced by two teeth, and the elytra without the marginal costiform 

 callosities, while in other specimens the horn is replaced by a tooth 

 and the marginal callosities are present on the elytral declivity as in 

 the normal males. 



Tribe Xyloperthini 



Xyloperthini Lesne, 1921, Assoc. Franc, pour l'Avanc. des Sci., Cong, de Stras- 

 bourg (1920), p. 288; 1924, Bostrychides de 1' Afrique Tropicale Franchise, 

 pp. Ill, 208-238; 1938, in Junk (pub.), Coleopt. Cat., pt. 161, pp. 55-68. 



This is a rather large tribe of Bostrichidae, containing many genera, 

 which are found in all parts of the world. Species belonging to 12 of 

 these genera are either established in the United States or have been 

 intercepted in commerce. 



KEY TO THE GENERA OF XYLOPERTHINI 



1. Pronotum without a carina along lateral margins, or the carina only 



indistinctly indicated at posterior angles 2 



Pronotum with a very distinct carina along lateral margins posteriorly, 

 sharply bent at posterior angles and slightly prolonged along base 10 



2. Antennal club composed of 4 segments Tetrapriocera Horn, p. 102. 



Antennal club composed of 3 segments 3 



3. Antenna with 8 or 9 segments 4 



Antenna with 10 segments 5 



4. Antenna with 9 segments Scobicia Lesne, p. 104. 



Antenna with 8 segments Octodesmus Lesne, p. 114. 



5. Segments of antennal club with sensory depressions on each surface 6 



Segments of antennal club without sensory depressions on either 



surface Xyloperthella, new name, p. 1 16. 



6. Apical declivity of elytra trituberculate on each side 7 



Apical declivity of elytra bituberculate on each side 9 



7. Lateral submargin on apical declivity of elytra very strongly elevated 



and acutely, angularly separated at sutural angles ; front of head convex 

 in both sexes; antennae densely pubescent-- Xyloprista Lesne, p. 117. 

 Lateral submargin on apical declivity of elytra not strongly elevated or 

 angularly separated at sutural margins 8 



8. Tubercles along anterior margin of apical declivity of elytra costiform, 



cylindrical, all obtuse at apices; antenna densely clothed with long 

 hairs; female with front of head flattened or concave, and anterior 



margin of pronotum with long hairs Xylomeira Lesne, p. 119. 



Tubercles along anterior margin of apical declivity of elytra subtriangu- 

 lar, all or at least 1 pair spinose at apices; antenna without, or 

 sparsely clothed with short hairs; female with front of head convex, 

 and anterior margin of pronotum without long hairs 



Xylobiops Casey, p. 121. 



9. First 2 segments of antennal club elongate, the first subtriangular; 



female with front of head flattened or concave, and last visible abdom- 

 inal sternite not emarginate at apex Dendrobiella Casey, p. 127. 



First 2 segments of antennal club subrounded or oval; female with 

 front of head convex, and last visible abdominal sternite very deeply 

 emarginate at apex Xyloblaptus Lesne, p. 130. 



10. Lateral margins of elytra very deeply, irregularly emarginate near 



apices Xylion Lesne, p. 133. 



Lateral margins of elytra not emarginate near apices 11 



11. First 2 segments of antennal club elongate; front of head of female 



with erect hairs Xylothrips Lesne, p. 135. 



First 2 segments of antennal club transverse; front of head of female 

 without erect hairs Xylopsocus Lesne, p. 139. 



