HALONIA. KNORRIA. 143 
Lycopodites.—Species of true Lycopodiaceze occur in ter- 
tiary marls; a beautiful specimen, from Germany, Lyco- 
podites Benettie, is figured Wond. p. 723. 
Hatonta ; Knorria. Lign. 41.—Associated with the plants 
already described from the coal-measures, there are trunks 
and branches of other trees, presenting peculiar and but 
imperfectly known characters, which it will be convenient to 
notice in this place. Fragments of these stems are to be 
seen in most public collections of the carboniferous flora, 
and should be examined by the student, for figures and 
descriptions can convey but an imperfect idea of their 
nature. 
Mr. Denny, the intelligent and indefatigable Curator of 
the Leeds Philosophical Society, has given the following 
admirable summary of the distinctive characters of the 
stems of most frequent occurrence in the Coal,* which will 
be found a useful guide to the collector. 
1. Sigillaria. — Stem furrowed, not branched, leaf-scars 
small, round, much narrower than the ridges of the stem. 
2. Favularia.—Stem furrowed, not branched, leaf-scars 
small, square, and as broad as the ridges of the stem. 
3. Lepidodendron. — Stem not furrowed, branched, 
covered with lozenge-shaped scars in quincuncial order, each 
having a papilla in the upper part; the upper portion of 
the stem and branches with simple linear leaves ; the lower 
portion destitute of leaves. 
4. Halonia.—Stem not furrowed, branched, covered with 
indistinct rhomboidal marks, and tubercular projections dis- 
posed in quincunx. 
5. Knorria.—Stem not furrowed, branched, marked with 
projecting scars of petioles disposed spirally. 
* On the Fossil Flora of the Carboniferous Epoch, with especial 
reference to the Yorkshire Coal-field. By Mr. Henry Denny, A.L.S. 
Proceedings of the Polytechnic Society of Yorkshire; for 1850. 
