Hide image in responsiveness

i am working on this sites responsive issue http://ift.tt/1vu9MgM here http://ift.tt/1C5TOFT

@media (max-width: 767px){
.span12 .row-dynamic-el:nth-of-type(2) .media_el .animation_right.start_animation:first-of-type{display:none;}}

but it is hiding two images the one with umbrella and one image with the map . i need to hide the one with umbrella on responsivenes. but it is hiding two images in the given above css . is there any other way in css3 to solve the issue? please help thanks