snark
connected, bridgeless cubic graph with chromatic index equal to 4
Watkins snark
a snark with 50 vertices and 75 edges
flower snark
infinite family of graphs
Foster graph
bipartite 3-regular graph with 90 vertices and 135 edges
Petersen graph
cubic graph with 10 vertices and 15 edges
double-star snark
graph with 30 vertices and 45 edges