In my mind the Baltimore is associated with the White Mountain butterfly as a survivor of a former geologic period. The latter was developed under colder conditions and now survives only on a few isolated mountain peaks; but the former has survived wherever the peat bog has held its sway during the long ages that the surrounding landscape has been taking on its present-day condition. Many things in the life of the Baltimore point to its primitive condition: the laying of the eggs in loose clusters, the long lethargy of the caterpillars, the limited flight of the butterflies--all indicate a creature with habits firmly fixed by long ages of development in a definite environment. No collector should feel sure that the Baltimore is not to be one of his trophies until he has visited in June every peat bog or sphagnum swamp in his locality. One may search years without finding it, and then come across a dozen in a single day. I well remember the interest with which I first found this species on the margin of a great swamp in Michigan when I was eager for every new butterfly to add to my collection. I had never seen it alive before and the thrill with which the first specimen was captured can be realized only by those remembering similar experiences. =Harris's Checker-spot= _Cinclidia harrisii_ This little butterfly so closely resembles the Pearl Crescent and the Silver Crescent that on the wing it is easily mistaken for them. It really looks more like them than it does the Baltimore Checker-spot, which is considerably larger and darker colored than the present species. This is essentially a northern form occurring only in a narrow strip of country east of Minnesota and Wisconsin, running on the north through southern Canada and on the south through Michigan, New York, and Massachusetts. This insect is one of the best-known botanists among all the butterflies. In the very difficult group of asters which has caused endless confusion to human botanists these insects seem always able to select the one species--_Aster umbellatus_. It has been repeatedly found that the caterpillars would starve rather than eat the leaves of other kinds of asters, and so far as known they have never been found feeding outdoors upon any other.