68 U.S. NATIONAL MUSEUM BULLETIN 2 79 



Figures 16-22 



16, TroxfronteraY auriG. First stage larva. 



17. Trox fronfera VauTie. Second stage larva. 



18. Trox frontera Vaurie. Third stage larva. 



19. Trox sordidus LeConte. Dorsal aspect of labium 



and hypopharynx. 



20. Trox sonorae LeConte. Second and third segments 



of antenna. 



21. Omorgus asper LeConte. Second and third segments 



of antenna. 



22. Trox sonorae LeConte. Lateral aspect of segments 7, 



8, 9, and 10 of abdomen. 



