In Boca Raton, FL, Jan. 8, 2006, David H. Costello, 94 of 5851 NW 25th Terrace, Boca Raton, FL formerly of Woodbridge and Wilton, CT. Son of the late Charles M. and Adele Hillman Costello, brother of the late Charles H. Costello and the late Frances Scott. Survived by 5 nieces and nephews. David graduated from Exeter Academy. He received a degree from Yale University in 1934. As a teacher, he taught mathematics at Hillhouse High School from 1934 to 1946. He was administrative assistant principal at Hillhouse High School from 1946 until his retirement in 1970. David was a Director of C. Cowles Co. on Water St., New Haven for many years and was a member of the Union League Club in New Haven. Funeral service and burial are private. BEECHER & BENNETT, 2300 Whitney Ave., Hamden is in charge of local arrangements. Memorial contributions may be made to CT Hospice, 100 Double Beach Rd., Branford, CT 06405.