492 
HABIT AND STRUCTURE OF CYCADEjE. 
rare in strata of the Transition, and Tertiary 
series, t 
The Cycadese form a beautiful family of plants 
whose external habit resembles that of Palms, 
whilst their internal structure approximates in 
several essential characters to that of Coniferse. 
In a third respect, (viz. the Gyrate Vernation, or 
mode in which the leaves are curled up at their 
t I learn by letter from Count Sternberg, (Aug. 1835.) that 
he has found Cycadesc and Zamites in the Coal formation of 
Bohemia, of which he will publish figures in the 7th and 8th 
Cahier of his Flore du Monde priraitif. This is, I believe, the 
first example of the recognition of plants of this family in strata 
of the Carboniferous series. 
During a recent visit to the extensive and admirably arranged 
geological collection in the Museum at Strasbourg, I was in- 
formed by M. Voltz that the stem of a Cycadites in that Museum, 
described by M. Ad. Brongniart as a Mantellia, from the Mus- 
chelkalk of Luneville, is derived from the Lias near that Town- 
M. Voltz knows no example of any Cycadites from the Muschel- 
kalk. Stems and leaves of Cycadese occur also in the Lias a* 
Lyme Regis. (Lind. Foss. FI. PI. 143.) 
The most abundant deposit of fossil leaves of Cycadeoc hr 
England, is in the Oolitic formation on the coast of Yorkshire, 
between Whitby and Scarborough, (See Phillips’ Illustrations of 
the Geology of Yorkshire.) Leaves of this family occur also in 
the Oolitic slate of Stonesfield. Lindley and Hutton, Foss. Flora, 
PI. 172, 175. 
In Lindley and Hutton’s Fossil Flora, PI. 136, Figures are 
given of Cones which he refers to the genus Zamia, from the sand- 
stone of the Wealden formation at Yaverland on the South coast 
of the 1. of Wight. 
M. Ad. Brongniart has established a new fossil genus Nilsonii^i 
in the family of Cycadese, which occurs at Hoer in Scania, 
strata, either of the Wealden or Green-sand formation ; and an- 
other genus, Pterophylhim, which is found from the New red 
sand-stone upwards to the Wealden formation. 
