A deer darted out onto Transit Road in Clarence last night, striking a motorcyclist and knocking him from the bike, state police said. James H. Huntz, 59, of Lockport, was riding a Kawasaki motorcycle when the deer ran out and into the side of the bike. Huntz lost control and crashed. He was treated at the scene by East Amherst Fire Department, then taken to the Erie County Medical Center, where he was listed in stable condition.