350 MR ROBERT KIDSTON ON THE FOSSIL FLORA OF THE 



Lacoe,. with the examples of Sphen. neuropteroides from Somerset, and find, as 

 suspected by Zeiller, that Pseudopecopteris anceps is identical with Sphen. 

 neuropteroides, with which species it must therefore be united. 



It is interesting to note that the British, as well as the American and 

 French, specimens of this fern appear to be infested with a species of 

 Excipulites. 



Localities : — Radstock ; Camerton ; Withy ; Clandown. 



Sphenopteris cristata, Brongt., sp. 



Sphenopteris cristata, Schimper, Traite d. paleont. veget, vol. i. p. 397. 



Sphenopteris cristata, Kidston, Catal. Palwoz. Plants, p. 74. 



Pecopteris cristata, Brongt., Hist. d. veget. foss., p. 356, pi. cxxv. figs. 4, 5. 



Remarks. — The only specimen of this species with which I have met is that 

 contained in the collection of the British Museum. 

 Locality : — Camerton. 



Ptychocarpus, Weiss, 1869, Foss. Flora d. jiingst. Stk u. d. Rothl, p. 94. 



Description. — " Sori round or oval, divided by a longitudinal cleft into two 

 oblong halves." 



Remarks. — The fruit of the genus Ptychocarpus appears to consist of two 

 sporangia lying side by side. The systematic position of the genus is near to 

 Asterocarpus ( = Pecopteris), but is separated from it by the sporangia being 

 arranged in pairs, whereas in the Aster ocarpus-Pecopteroids the fruit is com- 

 posed of several stellately arranged sporangia. In the type of Ptychocarpus 

 (P. hexastichus) the sporangia are surrounded by a narrow flat border, from 

 which Weiss thinks that the two sporangia were covered by an indusium, 

 which, springing from the centre of the medial line, extended over and beyond 

 the sporangia. 



He compares his genus Ptychocarpus to Didymochloena, Desv., and the 

 external resemblance of the upper surface of the fruiting pinnules of Didymoch- 

 lama sinuosa, as figured by Bauer,* to the species about to be described (P. 

 oblongus) is very striking. In pointing out this external resemblance I do not 

 at all infer any affinity between the recent and fossil genera. 



Ptychocarpus oblongus, Kidston, n. sp. 

 Plate XX. fig. 2. 



Description. — Frond tripinnate (?); pinnae subopposite, lanceolate ; pinnules 

 subopposite, oblong, usually bearing four pairs of oblong lateral lobes and a 

 terminal one. On each lobe is situated an oblong synangium (?), composed of 



* Bauer and Hooker, Genera Filicum, or Illustrations of the Ferns and their other Allied Genera,. 

 tahlc viii. figs. 2, 3. 



