This is a rare specimen of an Trilobite of the species  Albertella helena from the Cambrian of Nevada.
 

Here is a classcal Utah Trilobite of the species Asaphiscus wheeleri from the Wheeler Formation.

This is a Utah trilobite of the species Brachyaspidion microps from the Wheeler Shale Formation.

Here is an inexpensive specimen of a New York trilobite of the species Bumastus ioxus from the classic Rochester Shale.

This is a beautiful rolled  trilobite of the species Eldredgeops rana from the Devonian of New York. 

Here is an inexpensive specimen of a trilobite of the species Eldredgeops rana from the Devonian of New York.

Here is a detailed and relatively large Utah trilobite of the species Elrathia kingi from the Wheeler Shale.

Here is a nice and rare trilobite of the species Elrathia marjumi from the Pierson Cove Formation of Utah.

 Here is a trilobite cluster from the Lower Cambrian of California with the species Olenellus clarki.

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

Here is a inexpensive agnostid Trilobite of the species Ptychagnostus atavus from the Wheeler shale Formation of Utah.

This is a beautiful trilobite of the species Triarthrus beckii from the Utica shale of New York.

Here is a inexpensive specimen of the trilobite species Triarthrus beckii from the Ordovician period in the state of New York. Notably or regrettably, the hypostome of this trilobite is visible. It is feature that is otherwise difficult to show.

Here is a classic Triarthrus eatoni from the Utica Shale of New York.
The trilobite itself is about 19 mm long.