The seeds described by Lindley and Hutton as _Cardiocarpon acutum_ (fig. 444, p. 171) have been made by Arber[925] the type of a new genus _Cornucarpus_, the distinguishing feature being the triangular form and the apical horns of the wing. The seeds figured by Arber[926] from the Kent coalfield as _Cornucarpus acutus_ are, however, not identical with the type of Lindley and Hutton, which has the characters of _Samaropsis_. _Samaropsis_ is widely distributed in Permo-Carboniferous rocks in Europe and North America and is recorded also from India[927] (fig. 504), China[928], South Africa[929] (fig. 503), South America[930] (fig. 502, F, G) and Australia[931]. Some seeds of this form were certainly borne on Cordaitean plants (cf. fig. 480, A), but seeds of similar type have been found in organic connexion with the foliage of Pteridosperms (figs. 442, 445, pp. 167, 172). The Permian ‘cone-scales’ bearing seeds described by Geinitz as _Cardiocarpon triangulare_[932], represented by well preserved impressions in the Dresden Museum, appear to be of the _Samaropsis_ type: the same author referred some _Samaropsis_ seeds to the Conifer _Walchia_, but Weiss[933] dissents from this correlation as the seeds often occur in beds in which _Walchia_ is not represented. Renault states that the seeds of the fertile shoot described by him as _Cycadospadix Milleryensis_[934] from Autun [= _Strobilites Milleryensis_ (Ren.)] closely resemble _Samaropsis fluitans_ Daws. as figured by Weiss. The suggestion by White[935] that _Samaropsis_ seeds were borne on fertile leaves of _Gangamopteris_ adds a further difficulty to the use of the generic characters of _Samaropsis_ as criteria of systematic position. The Permian seeds figured by Goeppert[936] as _Oreodoxites Martianus_ are possibly specimens of _Samaropsis_. The designation _Samaropsis_, though usually restricted to Palaeozoic species, is applied by some authors to ‘winged’ seeds from Mesozoic strata; but as some of the Jurassic seeds[937] so named appear to have true wings like those of some recent Conifers it is advisable to adhere to the more limited use of the name. It is safe to assert that many _Samaropsis_ seeds agreed generally in structure with Cordaitean seeds such as the petrified examples described by Brongniart as _Cardiocarpus_. The species _Mitrospermum compressum_[938] is an example of a petrified seed having the external features of _Samaropsis_. =Cardiocarpus.=