While recognising a general resemblance to the sporophylls of _Isoetes_, certain differences are obvious: there is no ligule in the fossil leaves nor are there any distinct traces of vascular strands such as occur in the leaves of recent species. The form of the sporangium, more elongated than in the majority of recent forms, is compared by Saporta with that in a south European species _Isoetes setacea_ Spr. Such evidence as we have lends support to the inclusion of these Portuguese fossils in the genus _Isoetites_, but apart from the fact that we have no proof of any connexion between the stems and supposed sporophylls, the resemblance of the latter to those of _Isoetes_ is, perhaps, hardly sufficient to satisfy all reasonable scepticism. The generic name _Isoetopsis_ was used by Saporta as more appropriate than _Isoetes_ for some Eocene fossils from Aix-en-Provence which are too doubtful to rank as trustworthy evidence of the existence of the recent genus. The species, _Isoetopsis subaphylla_[151] is founded on impressions of small scales, 4 mm. long, bearing circular bodies which are compared with sporangia or spores. Other records of fossils referred to _Isoetes_ need not be described as they have no claim to be regarded as contributions towards the past history of the genus. Heer’s Miocene species _Isoetites Scheuzeri_ and _I. Braunii_ Unger[152] from Switzerland are based on unsatisfactory material and are of no importance. Pleuromeia. The generic name _Pleuromeia_, was suggested by Corda[153] for a fossil from the Bunter Sandstone, the original description of which was based by Münster[154] on a specimen discovered in a split stone from the tower of Magdeburg Cathedral. The majority of the specimens have been obtained from the neighbourhood of Bernburg, but a few examples are recorded from Commern and other German localities: all are now included under the name _Pleuromeia Sternbergi_. Germar, who published one of the earlier accounts of the species, states that Corda dissented from Münster’s choice of the name _Sigillaria_ and proposed the new generic title _Pleuromeia_. One of the best descriptions of the genus we owe to Solms-Laubach[155] whose paper contains references to earlier writers. Illustrations have been published by Münster, Germar[156], Bischof[157], Solms-Laubach and Potonié[158]. _Pleuromeia Sternbergi._ (Münster.) Fig. 134. 1842. _Sigillaria Sternbergii_, Münster. 1854. _Sagenaria Bischofii_, Goeppert[159]. 1885. _Sigillaria oculina_, Blanckenhorn. 1904. _Pleuromeia oculina_, Potonié.