36 Art. 8.— A. Kryshtofovich : 



tively strong midrib, attaining about 2/3 of the length of the leaf- 

 let. Of the form S. latifolia Font.^^ which is too large to com- 

 pare with our species, being 8-10 cm. in length, only the upper 

 part of the leaflet was observed. S. virglniensis Font.-^ is in a 

 similarly bad state of preservation. The specimens of S. elliptica, 

 figured by Berey,^^ do not show a very groat difference, except its 

 marked acnteness of the top. Sewaed has found resemblance bet- 

 ween S. virginlensis and the Jurassic S. paucifolia (Phill.) Waed, 

 but Beeey^^ mentioned its greater resemblance to S. Mantellli of 

 Wealden, having a midrib still less prominent. 



But perfect identity with our species is observed in S. variabilis 

 of the Cenomanian in Bohemia, represented by leaflets of a quite 

 similar outline, with the midrib sHghtly prominent only at the base 

 and branching towards the apex. Moreover, a great similarity is 

 observed in the assymetrical leaflets of both specimens from these 

 two locaUties so very distant from each other. The identification 

 of this plant by Yelenovsky with Thinnfeldia Lesquereuxiana was 

 cancelled in 1880 by himself as quite unfounded. 



I also can confirm the total difference of these two genera 

 Protophyllocladus {Thinnfeldia) and Sagenopteris, both represented 

 in my collections from Russian Sakhalin. 



The genus Sagenopteris occurs first in the Triassic and is very 

 prominent in the Ehaetic as well as the Jurassic ; while the Lower 

 Cretaceous species are mainly American, except S. Mantellii, which 

 is widely spread in Europe. S. neocomiensis H. and INI.,^^ of the same 

 type, has been recorded from Westphalia, but its specimens were 

 too fragmental. In the upper Cretaceous, we have only S. variabilis 



1) Fontaine (1889), p. 148, pi. XX VU, f. 10. 



2) Fontaine (1889), p. 150, pi. CXXXVm, f. 13 ; CXXXIX, f. 1. 



3) Beeky (1911 c), p. 287, fig. 4. 



4) Bebey (1911 c), p. 289. 



5) HositTs und Maeck (1880), p. 210, pi. XLIV, f. 194. 



