@keyframes slidy {
    0%, 30% {
        left: 0%;
      
    }
    35%,65%{
        left:-100%;
      
    } 
    70%,100% {
        left: -200%;
        
        } 
      
}

div#captioned-gallery {
    width: 100%;
    overflow: hidden;
    margin-top: -1%;
}

figure.slider {
    position: relative;
    width:500%;
    font-size:0;
    animation: 15s slidy infinite;
    
}

figure.slider figure{
    width:20%;
    height:auto;
    display: inline-block;
    position:inherit;
}

figure.slider img{
    width:100%;
    height:410px;
}