Maryland Geological Survey 245 



Frond bipinnate or tripinnate. Pinnas elongate, linear in outline/ 

 Pinnules approximate, variable in outline, usually obtuse and becoming 

 united distad to form a pinnatifid pinna, which is then constricted and 

 slightly decurrent at the base. Venation of the Cladophlehis type, not 

 well seen in the smaller pinnules because of their coriaceous texture. 



This is another cosmopolitan species of Cladophlehis which may be 

 composite in nature, and which, as commonly preserved in fragmentary 

 specimens, is distinguishable with difficulty from its congeners. It is 

 especially close to Cladophlehis Alhertsii and Cladophlehis Ungeri. It 

 is recorded from the uppermost Jurassic and lowermost Cretaceous in 

 Portugal, from the Neocomian of Japan and from the Wealden of Eng- 

 land, Germany, and Austria. From the late Jurassic or early Cretaceous 

 of Spitzbergen Nathorst describes a very similar form as Cladophlehis 

 sp. B." In America it has been reported from the Shasta through the 

 Horsetown and in the base of the Chico formation on the Pacific Coast, 

 and from the Kootanie formation of Montana and British Columbia. 



It is well scattered and abundant in the Potomac Group occurring in 

 all three of the formations but represented for the most part by incom- 

 plete specimens showing slight variations which were made the basis 

 for many species by Professor Fontaine. Material from the Patapsco 

 formation of Maryland shows indistinct oval sori in a single row on 

 either side of the midvein. These are of the type found associated with 

 a number of other American species of Cladophlehis. 



Professor. Zeiller ' has recently reported fertile fronds of Pecopteris 

 Browniana, or of a very similar species from the Wealden of Peru. 

 These are not figured but are described as having biseriate, oval, annulate 

 sporangia, as in the modem family Schizgeacege, and very like those of 

 the Jurassic genus Kluhia of Raciborski, thus apparently somewhat dif- 

 ferent from those of the American representatives of the present species. 



^ The single form which Fontaine identified with this species has pinnae 

 which shorten rapidly giving the frond a deltoid form, and may be properly 

 referable to the allied species Cladophlehis TJngeri. 



^Nathorst, Kgl. Svenska Vetens.-Akad., Handl., Band xxx. No. 1, 1897, p. 

 50, pi. ii, fig. 10. 



' Zeiller, Comptes rendus, tome cl, 1910, p. 1488. 



