Edit in JSFiddle

//各クラスを別々に取得
//開発ツールコンソール参照

jQuery(function(){
    jQuery(".head").each(function(e,v){
        console.log(v);
    });
    jQuery(".contentns").each(function(e,v){
        console.log(v);
    });
});

<div class="body">
    <div class="head">
        headA
    </div>
    <div class="contents">
        contentsB
    </div>
</div>
<div class="body">
    <div class="head">
        headB
    </div>
    <div class="contents">
        contentsC
    </div>
</div>
<div class="body">
    <div class="head">
        headC
    </div>
    <div class="contents">
        contentsD
    </div>
</div>