corda's extinct flora. 121 



maria anahathra, are uniformly and regularly scalariform, whereas 

 in the other they are porous or dotted vessels. Moreover, this latter 

 has two distinct sets or orders of medullary rays — several smaller or 

 secondary rays occurring between every two of the principal ones. 

 S, anabathra has only the large or principal rays. It is very possi- 

 ble that the S.Jicoides of Corda may exist in this country as well as 

 the other kind, but as yet it is known only as a production of the 

 coal-mines of Bohemia. 



3. The tribe DiploxylecB contains only a single species, the Di- 

 ploxylon cycadeoideum, first discovered by M. Corda, and described 

 by him in the year IS^O. Nothing is known of it except the struc- 

 ture of the stem, which is peculiar, being composed of two distinct 

 ligneous bodies or zones, the outer of which consists of vessels ar- 

 ranged in radiating lines, the inner of vessels crowded together with- 

 out any order. All the vessels in both zones are of the scalariform 

 structure ; and it is remarkable, indeed, how extensively this pecu- 

 liar kind of tissue is found to prevail in the fossil plants of the older 

 formations. 



4, 5. The author's observations on the Cycadece contain nothing 

 very new or important ; and under the head of Palms, the most 

 material novelty is the discovery of wood belonging to this tribe, or 

 at any rate to the Endogenous class, in the coal-mines of Bohemia. 

 It occurs, he says, only in small fragments imbedded in nodules of 

 the mineral called Sphaerosiderite (a carbonate of iron). This disco- 

 very is the more important, as Adolphe Brongniart has lately denied 

 altogether the existence of Endogens in the coal-formation. 



6. Concerning the Flabellaria borassifolia of Sternberg, much 

 new and valuable information is here communicated. It is shown, 

 that what its original describer took for the segments of a fan-shaped 

 leaf, are in fact (as Brongniart had already suspected) simple leaves, 

 crowded together into a fan-like tuft at the top of the stem. The 

 straight and parallel veins of these leaves give to the plant the ap- 

 pearance of an Endogen, but the internal structure of the stem, here 

 for the first time described, is totally at variance with that of the 

 Endogenous class. The wood forms a hollow cylinder, entirely 

 composed of scalariform vessels, which are regularly arranged in 

 radiating lines, but without medullary rays ; this cylinder encloses a 

 large central pith, and is itself surrounded by a zone of cellular tis- 

 sue, through which bundles of scalariform vessels run out to the 

 leaves. In the form and position of this vascular cylinder, as well 

 as in the nature of the tissue composing it, Flabellaria agrees on the 

 one hand with the Sagenariaceae or Lepidodendrea?, on the other 

 with the Sigillarioe ; but from the former it differs in the distinctly 

 radiated arrangement of its vascular tissue, from the latter in the 

 absence of medullary rays. 



The other fossil plants included under the genus Flabellaria in 

 Unger's Synopsis are widely different from this, and arc referred 

 by Corda to the Palm tribe, under the generic name of Borassitcs. 



7. Under the head of Orchidece is described a remarkable fossil, 

 of which the locality is unknown. It is a mass of matted roots, si- 



