Here is a Nevada Trilobite of the species Olenellus gilberti with a nice and attractive preservation.

Here is a beautiful and inexpensive example of a Nevada Trilobit of the species Olenellus gilberti.

Here is a inexpensive Nevada Trilobite of the species Olenellus gilberti with a attractive colour and great contrast.
 

This is a fairly large and inexpensive example of a Nevada trilobite of the classic species Olenellus gilberti.
 

This is a piece with servile Nevada Trilobites of the relative rare species Syspacephalus various from the Emigrant Fm.. Some of the specimens are preserved as negative.

Here is a classical Trilobite of the species Triarthrus beckii from the upper Ordovician of the New York State.