You will have the option to choose what level of identification you would like to reach. It is recommended that you start out on the order level and work your way down if you are a beginner. If you already know the order level of your specimen, you can start the identification process on the family key. If you are more experienced and have already identified the specimen down to the family you may start at the genus key.
The field guide consists of a series of couplets (two descriptions of features the specimen may or may not have). You will choose the the description that best fits your specimen. Photographs will accompany the couplets for clarification of the key features being addressed in the couplets. Choosing a description may bring you to another couplet until you have reached the appropriate answer for your specimen.
Please note that not all specimens are "perfect" specimens and that some appendages and gills may be missing, both in the photographs and on your specimens. This field guide is also limited by what specimens are available for this field guide.