Are nodes atomic values?

My question is, is there a XPath that selects a node such as i get the
same as if i did a

<xsl:copy>
   <xsl:apply-templates select="*[not(SomeNode)]"/>
</xsl:copy>

or with a example, giving this node

<Menu>
   <Name>aaa</Name>
   <SomeNode>xxx</SomeNode>
</Menu>

is there a XPath expr that selects only

<Menu>
   <Name>aaa</Name>
</Menu>

?

I'm asking this because i think in the problem i've posted yesterday
the time elapsed grows with the quantity of data selected on the
recursive template i'm using, on FF, i mean, and i like to test this
assumption.

Thanks