1: Confident to an extreme
7: Archaeology venue, at times
9: Salt who passes the salt, e.g.
22: '___ Town Too' (1981 hit for James Taylor and J.D. Souther)
27: Blended-family prefix
36: Claustrophobia, for one
38: Microorganisms' locomotion
41: Charges for admission
47: They may be calculated
48: Lewis Carroll's 'Jabberwocky' word for 'scratch, dog-style'
51: It may be Olympic-sized