This generic name, proposed by the late Professor Weiss[988], is applied to a type of fructification illustrated by the plant which Brongniart named _Pecopteris unita_, a species common in the Upper Coal-Measures of England[989]. It is adopted by Kidston for fertile specimens from Radstock which he describes as _Ptychocarpus oblongus_[990], but the precise nature of the fertile pinnules of this species cannot be determined. _Ptychocarpus unita_ (Brongn.[991]). Fig. 291, A, B. (= _Goniopteris unita_, Grand’Eury.) This species has tripinnate fronds with linear pinnae bearing contiguous pinnules of the _Pecopteris_ type (fig. 291, B), 4–5 mm. long, confluent at the base or for the greater part of their length. On the under surface of the fertile segments, which are identical with the sterile, occur circular synangia (fig. 291, A) consisting of seven sporangia embedded in a common parenchymatous tissue and radially disposed round a receptacle supplied with vascular tissue. The synangium is described as shortly stalked like those of _Marattia Kaulfussii_ (fig. 245, B′, p. 320). In shape, in the complete union of the sporangia, and presumably in the apical dehiscence, _Ptychocarpus_ agrees very closely with _Kaulfussia_ (fig. 245); but we cannot be certain that we have not a collection of microsporangia simulating a fern synangium. A synangium closely resembling _Ptychocarpus_ has been described by Mr Watson[992] from the Lower Coal-Measures of Lancashire as _Cyathotrachus altus_, but there is no convincing evidence as to the nature of the plant on which it was borne. _Danaeites._ This generic name, instituted by Goeppert[993], has been used by authors without due regard to the nature of the evidence of affinity to _Danaea_. The type named by Stur _Danaeites sarepontanus_[994] (fig. 291, E) bears small pecopteroid pinnules with ovoid sporangia in groups of 8–16 in two contiguous series on the lower face of the lamina. The sporangia dehisce by an apical pore and are more or less embedded in the mesophyll of the segments. No figures have been published showing any detailed sporangial structure, and such evidence as we have is insufficient to warrant the conclusion that the resemblance to _Danaea_ is more than an analogy. _Parapecopteris._ _Parapecopteris neuropteroides_, Grand’Eury. Fig. 290, D. The plant described by Grand’Eury[995] from the Coal-fields of Gard and St Étienne, and made the type of a new genus, is characterised by pinnules intermediate between those of _Pecopteris_ and _Neuropteris_[996] and by the presence of two rows of united sporangia along the lateral veins, as in _Danaea_ and _Danaeites_. _Asterotheca._