Several examples of effigy-mounds are found in Ohio. The most notable one is that known as the Great Serpent Mound, in Adanis County. We give an illustration of it. The entire surrounding country is hilly. The effigy itself is situated on a tongue of land formed by the junction of a ravine with the main branch of Brush Creek, and rising to a height of about one hundred feet above the creek. Its form is irregular on its surface, being crescent-shaped, with the point resting to the north-west. We give in a note some of the dimensions. The figure we give of this important effigy is different from any heretofore presented. We are indebted for the plan from which the drawing was made to Rev. J. P. MacLean, of Hamilton, Ohio. Mr. MacLean is a well-known writer on these topics. During the Summer of 1884, while in the employ of the Bureau of Ethnology, he visited the place, taking with him a thoroughly competent surveyor, and made a very careful plan of the work for the Bureau. All the other figures published represent the oval as the end of the works. Prof. Putnam, who visited the locality in 1883, noticed, between the oval figure and the edge of the ledge, a slightly raised, circular ridge of earth, from either side of which a curved ridge extended towards the sides of the oval figure. Mr. MacLean’s researches and measurements have shown that the ridges last spoken of are but part of what is either a distinct figure or a very important portion of the original figure. As figured, it certainly bears a very close resemblance to a frog, and such Mr. MacLean concludes it to be.