Regarding _L. laricinum_ of Sternberg as the type of the genus, and taking in connection with this the species described by Goldenberg, and my own observations on numerous specimens found in Nova Scotia, 1 have no doubt that _Lomatophloios crassicaulis_ of Corda, and other species of that genus described by Goldenberg, _Ulodendron_ and _Bothrodendron_ of Lindley, _Lepidodendron ornatissimum_ of Brongniart, and _Halonia punctata_ of Geinitz, all belong to this genus, and differ from each other only in conditions of growth and preservation. Several of the species of _Lepidostrobus_ and _Lepidophyllum_ also belong to _Lepidophloios_. The species of _Lepidophloios_ are readily distinguished from _Lepidodendron_ by the form of the areoles, and by the round scars on the stem, which usually mark the insertion of the large strobiles, though in barren stems they may also have produced branches; still, the fact of my finding the strobiles _in situ_ in one instance, the accurate resemblance which the scars bear to those left by the cones of the red pine when borne on thick branches, and the actual impressions of the radiating scales in some specimens, leave no doubt in my mind that they are usually the marks of cones; and the great size of the cones of _Lepidophloios_ accords with this conclusion. The species of _Lepidophloios_ are numerous, and individuals are quite abundant in the coal formation, especially toward its upper part. Their flattened bark is frequent in the coal-beds and their roofs, affording a thin layer of pure coal, which sometimes shows the peculiar laminated or scaly character of the bark when other characters are almost entirely obliterated. The leaves also are nearly as abundant as those of Sigillaria in the coal-shales. They can readily be distinguished by their strong, angular midrib. The markings of _Lepidophloios_ may easily be mistaken for those of the _Clathraria_ type of _Sigillaria_. When the stem only is seen, they can be distinguished by the length of the leaf-bases in _Lepidophloios_, and by the dominant central vascular scar; also by the one-nerved and ribbed leaves. Where the large, round marks of the cones are present, these are an infallible guide, never being present in _Sigillaria_. As the cones grew on the upper sides of the branches, the impression of the lower side often shows no cone-scars, or only two lateral rows, whereas on the upper side of the same branch they appear spirally arranged. I may describe as an example--