Hoplolichoides conicotuberculatus (Nieszkowski, 1859). This trilobite was found in the Vilpovitsy quarry (Asery Level), St. Petersburg region, Russia 

Dates to the Middle Ordovician Period. 

Size: Trilobite - 4.5 cm (outstretched) x 3.5 cm.   
Matrix: 8.0 cm x 9.0 cm x 4.0 cm

The hard calcite exoskeleton shows up nicely against the lighter limestone matrix. 

Please note that these Russian trilobites always have a small amount of restoration, this trilobite has approximately 6-7% restoration.