Today there is an increasing recognition among taxonomists of the importance of consideration of the complete morphology of insects in classifying them and in arrangming them in their logical phylogenetic sequence. Regarding the Rhynohophora, with which this paper is concerned, some progress toward a more complete understanding has been made. In 1912 Sharp and Muir made a study of the male genital tube of the coleoptera in general and observed that the various specializations they noted in the forms of Rhynohophora examined would doubtless be of future significance. Tanner in 1927 made a similar important study of the female genitalia and subsequently has included both the male and the female genitalia in desciprtions of new species, as noted in his study of the subtribe Hydronomi. Stickney in 1923 examined and repoted his findings on the head capsule. Boving and Craighead in 1931 published the results of their studies of the larval forms. Ting in 1936 compiled the results of a rather comprehensive study of the mouth parts of the Rhynohophora alone.

The axillary sclerites of 69 species representing 52 families of the order Coleoptera were examined and illustrations prepared of most or them. A description is given for the typical axillary sclerites and the deviations in form from this pattern are discussed for the major groups of beetles. The phylogenetic relationships between some families, and other groups, are pointed out based on the morphology of the axillary sclerites. Phyletic groups in Adephaga are characterized by the axillary sclerites, but in the Polyphaga variations are too numerous and inconsistant to be useful in determining phyletic trends.