I found this a great book for getting a start on butterfly identification. I wanted something limited to my part of North America since I have found that field guides that cover the whole continent are overwhelming and time-consuming to use when first trying to get to know any group of plants or animals. The book is easy to flip through rapidly. You need only look at the lefthand pages to quickly review a group of butterflies. Most double page spreads show both the dorsal (upperside) and ventral (underside) views of both the fore and hind wings. Family and subfamily are at the bottom of the pages and there is a useful monthly occurrence chart (phenogram) under each picture. Each picture also includes a bar that indicates the actual wing span of the species--a very useful device I haven't seen in other butterfly books. Textual notes include the "Nature Notes" which give behavioral or other useful information for making ids.
The standard text sections for each species include: Description, Similar Species, Life Cycle, Eggs, Caterpillar, Chrysalis, Wintering, Caterpillar Food, and Adult Food. The descriptive text is excellent. It gives a description from above and from below and provides clear references to the field mark lines which indicate key points in the photos.
All in all, this is a superb field guide if you are interested in the butterflies of New England. I have compared it to the Kaufman Focus and Petersen field guides on butterflies and it seems to lack nothing for someone whose focus is on the northeast.
It's even sized to fit into your pants pocket and weighs about 1/3 what a "standard" field guide weighs.
I'd say this book may currently be a sleeper, but is destined to become a classic.
