Examination of 283 adult and subadult skulls for malformation of the frontal sinuses revealed only ten that were not obviously malformed. Two were from New York, one from Massachusetts, one from Pennsylvania, and six from the 52 specimens from Michigan and Wisconsin. In addition, skulls of many young and even juveniles were malformed. _Specimens examined._--Total number, 555, arranged alphabetically by states and provinces and, unless otherwise noted, from north to south by counties in each state. Except as otherwise noted specimens are in the United States National Museum. =Alabama.= _DeKalb County_: Fort Payne, 1. =Connecticut.= _Litchfield County_: Riverton, 1[5]; Gaylordsville, 1. _Hartford County_: East Hartford, 4 (3[5]); Glastonbury, 2[5]; South Glastonbury, 4[5]. _Windham County_: Plainfield, 2 (1[14]). _Fairfield County_: Greenwich, 2[2]. _New London County_: Liberty Hill, 35 (33[75], 2[7]). =District of Columbia.= Washington, 3; near Washington, 1; Eastern Branch, 1; Congress Heights, 1; Benning, 1; no definite locality, 1. =Georgia.= _Towns County_: Young Harris, 1. _Cherokee County_: Canton, 1. _Cobb County_: Roswell, 1[81]. =Indiana.= _St. Joseph County_: Notre Dame, 2[99]. _Porter County_: Hebron, 1. _Miami County_: Denver, 5 (4[75], 1[4]). _Wells County_: Bluffton, 1. _Howard County_: Russiaville, 1. _Jay County_: Salamonia, 1[2]. _Boone County_, 1[2]. _Knox County_: Bicknell, 3. =Illinois.= _Lake County_: Camp Logan, 3[60]; Fort Sheridan, 1[60]. _Cook County_: W Northfield, 2; Flossmoor, 1[60]; no locality more definite than county, 1. _Du Page County_: Bloomingdale Spg., 1[60]. _Carroll County_: Savanna, 1[87]. _McLean County_: Normal, 1[7]. _Champaign County_: Harwood Township, 1[7]. _Pike County_?: Milton Spring, 1[60]. _Pope County_: Golconda, 3. =Kentucky.= _Woodford County_: Midway, 1. _Hancock County_: Hawesville, 1. =Maine.= _Oxford County_: Upton, 1[75]; Bethel, 1[74]. =Maryland.= _Howard County_: Long Corner, 1; Hanover, 1. _Montgomery County_: Gaithersburg, 1; Garret Park, 1; Chevy Chase, 1; Bethesda, 1. _Prince Georges County_: Laurel, 18; Plummer Island, 3; Oxon Hill, 1. _Talbot County_: Easton, 1. _Dorchester County_: Cambridge, 5[40]. =Massachusetts.= _Middlesex County_: Wilmington, 6; Burlington, 6; Lexington, 1[75]; Wayland, 2[75]. _Berkshire County_: New Marlboro, 1[5]. _Worcester County_: Lunenburg, 2; Lancaster, 1[75]; Princeton, 2[75]. _Norfolk County_: So. Weymouth, 1[75]. _Plymouth County_: Wareham, 5[75].