What saint has a feast day of July 1?

On July 1st the following saints are honored:

Aaron of Caerleon

Antonio Rosmini-Serbati

Arnulf of Mainz

Calais of Anisole

Castus of Sinuessa

Cewydd

Domitian of Lerins

Eparchius of Perigord

Gall of Clermont

Golvinus of Leon

Jan Nepomuk Chrzan

Julius of Caerleon

Junipero Serra

Juthware

Leonorius of Brittany

Martin of Vienne

Nazju Falzon

Oliver Plunkette

Regina of Denain

Secundinus of Sinuessa

Servan of Culross

Sherfute

Simeon the Gaul

Theodoric of Mont d'Or

Thomas Maxfield

Veep