_Samaropsis_. Goeppert[922] defined _Samaropsis_ as ‘Fructus samaroideus membranaceus, compressus, margine alatus, monospermus.’ The type-species, _S. ulmiformis_, from the Permian of Brenau, is a small seed with a broad wing or border, but a better example of _Samaropsis_ is figured by Goeppert as the wing of an insect[923]. Examples of the genus are shown in figs. 502, A–H; 503; 504. Seeds included in _Samaropsis_ differ from those referred to _Cordaicarpus_ in the presence of a broader and more clearly defined border which in some cases, as in the genus _Mitrospermum_ (fig. 494, K, L), undoubtedly represents a lateral wing-like extension of the sarcotesta. In some instances the wing may be a tangentially expanded integument comparable with the perianth of _Welwitschia_, and in some Jurassic seeds referred by Heer[924] to _Samaropsis_ the lateral appendages are probably true wings. It is advisable to restrict the designation _Samaropsis_ to Palaeozoic seeds. Nucules deprived of the broad border would be referred to _Cordaicarpus_ as usually employed for impressions. The generic name _Samaropsis_ serves a useful purpose as a distinctive term for platyspermic seeds preserved as casts or impressions characterised by the possession of a wide border or wing broader than in typical examples of _Cordaicarpus_. The specimen represented in fig. 499 affords a good illustration of the difference between _Samaropsis_ and _Cordaicarpus_. In this specimen the border clearly consists of two portions, an inner narrower border (black in the drawing) and an outer more delicate portion; the former is the impression of the sclerotesta and the outer represents the fleshy sarcotesta which in the living seed may have formed a wing. If, as often happens, the seed were preserved with the narrow border only it would be assigned to _Cordaicarpus_, many species of which are undoubtedly incomplete _Samaropsis_ seeds.