PROCEEDINGS OF THE ENTOMOLOGICAL SOCIETY OF WASHINGTON VOL. 22 JANUARY, 1920 No. 1 BIOLOGY OF SOME COLEOPTERA OF THE FAMILIES COLYDIIDAE AND BOTHRIDERIDAE. Bv F. C. CRAIGHEAD, V. S. Bureau of Entomology. Several species of the family Colydiidae which show very dif-ferent larval structures and habits have been reared by the writer. These forms were grouped by the older systematists in the family Colydiidae which included the Bothrideridae, but the latter have since been separated as a distinct family. An anal-ysis of the available larvae substantiates the erection of the forms allied to Bothrideres to family rank. In fact, the two types, as represented by the last named genus and Aulonium have very few fundamental characters in common. The material here de-scribed is from the U. S. National Museum and Forest Insects Collections. The larvae of some of the European species 1 of these families have been described but none of the North American forms. In fact, several records of food habits constitute the entire pub-1 Aulonium trisulcum Geoffr. Westwood-Trans. Ento. Soc. London, 1839. Aulonium ruficorne Oliv. (A. bicolor Herbst). Perris-Insectes du Pin Maritime, 1853. Aglenus brunneus Gyll. Rey-Ann. Soc. Linn., 1887. Cerylon histeroides F. Erichson-Naturgeschichte der Insecten Deutch-lands-Erste Altheilung, Coleoptera, Berlin, 1848. Colobicus margitiatus Latr. Perris-Larves des Coleopteres. 1877. Colydium filiforme F. Ratzeburg-DieForstinsecten. 1837. Ditoma crenata Fabr. Perris-Insectes du Pin Maritime, 1853. Synchitahumeralisf (Ditoma juglandisf.). Nordlinger-Stettin. Ento. Zeit. p. 256, Vol. 9, 1848. Endophloeus markovichiana Pill. (sf>i>iulosns Latr.). Perris -Larves Coleopteres, 1877. Langelandia anopthahtui Aubc. Perris Larves des Coloepteres, LS77. Orthocircus clavicornips (nuiticus) L. Rupcrtsberger Verhdl. Zoo. Bot. Ges. Wien. p. 7-28, 1872. Synchitodes crenatus Herbst. Perris Insectes du Pin Maritime, is.".:;.