Affinities o/Archeeopteris hibernica, Forbes. 413 



costate (" sovis (sporangiis ?) costulatis ") . He givea an 

 enlarged drawing of the sporangia at pi. xxxvi. fig. 4. 



More recently Mr. Carrutliers redescribed the fruit of 

 this fern *. Among other things he says : — " In some 

 specimens in the British Museum all the lower pinnee are 

 entirely fertile. I am satisfied that the ovate-oblong sori are 

 generally single, and not clustered, and are two-lipped, the 

 slit passing one third of the way down the sorus. The vein 

 is continued as a free receptacle in the centre of the cup or 

 cyst, as in existing Hymenoptujllece, in which it is included, 

 not reaching beyond the entire portion. In some specimens 

 the receptacle is broad or thick, indicating the presence of 

 something besides itself in the cup, and giving the appear- 

 ance that would be produced if it were covered with spo- 

 rangia ; I cannot, however, detect any indication on the outer 

 surface which might have been expected from the individual 

 sporangia. The compression of the specimens in the rock, 

 wliich has made the free receptacle appear like a vein on the 

 wall of the cup, together with the highly altered condition of 

 the rock in which the fossils are contained, account for the 

 imperfect preservation of the minute structures. 



" The interpretation which I have here given of the fructi- 

 fication of this interesting fossil exhibits so close a resem- 

 blance to what we find in the living genus Hymenophyllani 

 that, were it not for the vegetative portions, I would without 

 hesitation place it in that genus." 



Crepinf, in 1874, figured and described some specimens of 

 Arcliceojjteris [Paheopteris) hibernica, var. minor, from 

 l^vieux, Belgium, of which he also figures the fruit, but does 

 not describe it in detail. 



As the generic name PalcBopteris , adopted by Schimper for 

 this and some allied ferns, had been previously employed by 

 Geinitz :j: for a fossil which he supposed to be a fern-stem 

 (but which has been discovered to be the stem of Cordaites), 

 iJawson §, in 1882, proposed the name Archceopteris for the 

 plants placed in Paloiopteris, Schimper (not Geinitz). Daw- 

 son's genus Archceopteris must tlierefore be employed for 

 Cyclopteris hibernica and its generic associates, as Palceopteris, 



* Geol. Mag. vol. ix. no. 2, Feb. 1872. 



t " Description de quolques plantes fossiles do I'^tage des psammitea 

 du Condroz (Devouien superieur)," Bull. Acad. roy. d. Belgique, 2' s<5r. 

 vol. xxxviii. no. 8, Aug. 1874. 



X Vers. d. Steiukf. in Sachsen, p. 32 ; see also Grand'Eury, 'Flore car- 

 bon, du D6part. de la Loire,' pp. 241 and 243, 



§ Foss. Plants of the Erian (Devonian) and Upper Silurian Formations 

 of Canada, part ii. p. 5)8 (1882j. 



