Most efficient way to search only some children of div?

Most efficient way to search only some children of div?

Given this sample HTML:

<div>
      <span class="searchme">some text</span>
      <span class="ignoreme">some more text</span>
      <span class="searchme">yet more text</span>
      <span class="ignoreme">finally some last text</span>
</div>

What is the most efficient way to determine if some search text is found within the div and ONLY in any one of the spans inside with a class of searchme? I can think of some convoluted ways but am hoping I've missed something fairly elegant and simple :) Right now the simple solution is eluding me.

TIA,

Kathryn