By no means an expert, but.. here is a pic of a Silver Hatchet. I kept 12 a few years ago. Just a friendly word of caution, they are notorious jumpers. Even with good fitting lids, a few managed to jump out.
There are several species, across a couple of Genera, that are often called Silver Hatchets. This one is called Common because it is the most frequently seen Silver Hatchet, ergo, the most "common".