NORTH AMERICAN BOSTRICHIDAE 127 



Elytra at base subequal in width to pronotum along middle; sides 

 nearly parallel, conjointly broadly rounded at apices; surface densely 



clothed with short, recumbent, brownish hairs, except at base, densely, 

 rather coarsely, shallowly punctate on disk; apical declivity impunc- 

 tate or very finely punctate, the sutural margins slightly, broadly ele- 

 vated, and lateral margins very strongly elevated ; each elytron with 

 three more or less distinct, longitudinal costae, and with three costi- 

 form tubercles along anterior margin of apical declivity, the tubercles 

 lung, and spinose at apices. 



Abdomen beneath finely, densely granulose or punctate, densely 

 clothed with rather long, recumbent, whitish hairs ; last visible sternite 

 twice as long as preceding sternite, and broadly rounded or subtruncate 

 at apex. 



Female. — Differs from the male in having four to six distinct tuber- 

 cles on the front of the head, and the last visible abdominal sternite as 

 long as the preceding two sternites united, transversely, arcuately car- 

 inate at the middle, and produced into a lobe, which is obtusely rounded 

 at the apex. 



Length 3-5 mm., width 1.4r-1.75 mm. 



Type locality. — Colorado Desert, Calif. ; type in the LeConte Col- 

 lection in the Museum of Comparative Zoology, Cambridge, Mass. 



Distribution. — From material examined: 



Aeizoxa: Santa Rita Mountains, May and June (Hubbard and Schwarz, and 

 M. Chrisman). Catalina Springs, April (Hubbard and Schwarz). Hot Springs 

 (Barber and Schwarz). Sabino Canyon (G. Hofer). Redington (M. Cbris- 

 rnan). Tucson Mountains, March 9, 1937 (G. P. Englehardt) . Tucson, July 

 (Hubbard and Schwarz, J. L. Webb, and H. F. Wicfcham). 



This species has been also recorded in the literature from Cali- 

 fornia, Lower California, and Mexico. 



Host. — This species has been reared a number of times from various 

 localities in Arizona from mesquite (Prosopls juliflora (Swartz) de 

 Candolle). 



LeConte (1S5S) reported sextuberatdatus as being abundant in the 

 Colorado Desert, Calif. 



Genus DEXDROBIELLA Casey 



Dendrobiella Casey, 1898, N. Y. Ent. Soc. Jour. 6 : 66, 67-6S, Lesne, 1901, Soc. Ent. 

 de France Ann. (1900) 69: 475, 489-497, figs. 271-284; 1933, C. R. Congr. Soc. 

 Savantes de Paris, p. 237, f. (publication not available) : 1938, in Junk i pub. >. 

 Coleopt. Cat., pt. 161, pp. 55-56. 



Head deeply inserted in prothorax, not visible from above ; clypeus 

 strongly transverse, truncate in front, with a small tooth on each side 

 at base of labrum: labrum short, transverse, truncate and densely 

 ciliate with long, yellow hairs in front; mandibles dissimilar, right 

 mandible attenuate toward apex, left mandible toothed on inner 

 margin, more strongly in female ; eyes very large, oval, globose, strong- 

 1}' projecting. Antenna short, 10-segmented; first and second seg- 

 ments robust, first flattened and arcuate beneath, second elongate, 

 much shorter than first; third to seventh segments small, transverse. 

 compact, united shorter than first : last three segments forming a large. 

 loose, compressed club, densely clothed with short, recumbent hairs, 

 each with two rows of small, round, sensory depressions on each sur- 

 face, the eighth subtriangular or securiform, ninth broadly oblong, and 



