FILICES. 137 



group of Cyclopteridae according to the shape of the lamina of the leaf, 

 one or two of which may be noticed because their great antiquity makes 

 them particularly interesting. One is the Devonian Palaeopteris, Schpr ; 

 the large handsome bipinnate leaves of P. hibernica, Forbes, are character- 

 istic of the Old Red Sandstone of Ireland, and will be found figured in 

 Schimper 1 . Several other species are known, chiefly from Canada 2 . 

 Triphyllopteris Collombi 3 and Cardiopteris Kochlini 4 are found in the 

 Culm together with finely divided Sphenopteridae. The latter plant is 

 marked by its fine roundish pinnae which are attached to the rachis by a 

 broad base. Most of the forms of this type from the Coal-measures 

 belong to the genus Odontopteris 5 . 



After elimination of the genera founded on the form of the entire 

 leaf, we have still a remainder of single pinnae of a highly problem- 

 atical character. Some of the forms which were once classed with them 

 are now seen to be leaves of Salisburieae, and have been already noticed in 

 their proper place (see p. 62) ; others are certainly Aphlebiae belonging to 

 various species of Ferns, the nervation of Cyclopteris being the prevailing, 

 though not perhaps the only, kind in these anomalous pinnae. If Saporta's 

 views respecting the Dolerophyllae discussed above on p. 125 should ever 

 be confirmed, a number of Cyclopteridae would once more be included in 

 that group. 



If now we proceed to the forms in which the nerves anastomose, we 

 have first Nervatio Goniopteridis, which arises out of Pecopteris when the 

 corresponding tertiary nerves which proceed from every two adjoining 

 secondary nerves anastomose with one another. This may happen, as we 

 know, in the case of all or sometimes only of the lowermost of the tertiary 

 nerves. A number of such Goniopteridae are known from the Tertiary 

 formations 6 , but it would take too long to ascertain to what extent they 

 and the allied nervation-forms, Goniophlebii, Pleocnemiae, Cyrtophlebii, etc. 

 are distributed through the Mesozoic deposits, for the figures and descriptions 

 of authors are not clear and distinct enough for the purpose. The forms 

 in question are however usually collected together under the generic name 

 of Phlebopteris ; all that have simple anastomosing nervation have 

 extremely few representatives in the Palaeozoic formations, the two chief 

 types, both belonging to Goniopteris, appearing in the Carboniferous species 

 Goniopteris (Diplazites) emarginata 7 and G. arguta 8 . 



Of fossil genera belonging to types with complex anastomoses we find 

 that the greater number are also first seen in the Mesozoic formations. 

 Only two of these are older and peculiar to the Coal-measures, Dictyo- 



1 Schimper (1), t. 36, and (2), p. 113. a Dawson (1). s Schimper (2), p. 114. 4 Schimper 

 (1), t. 35, and (2). p. 118. 5 Schimper (2), t. 30, f. 14, and (2), p. 121. * Schimper (IX and 

 A. Braun (1). 7 Goppert (2), t. 16, ff. i, 2. ' Brongniart (1\ t. 108, ff. 3, 4. 



