Nœggerathia.[154]--I must briefly notice the coal-plants which M. Brongniart has placed under this genus, because the foliage of some species appears to have entered largely into the formation of certain seams of coal, although the perfect form of the leaves is unknown. The foliage referred to Nœggerathia consist of pinnated, or deeply pinnatifid, simple leaves. These leaves, or leaflets, are either elongated, linear, lanceolate, wedge-shaped or flabelliform, and entire, or deeply lobed at their extremity, and are traversed by numerous, fine, equal nerves, slightly diverging from the base, but almost parallel. The affinities of these plants are not satisfactorily made out: M. Brongniart considers them to approach nearest to the Cycads or Conifers; perhaps forming a connecting tribe between those two great groups of gymnosperms.[155] [154] A leaf of _N. flabellata_ is figured in Foss. Flor. [155] Tab. Veg. Foss. p. 64. Fossil Resins.--Amber.--The resinous secretions of Conifers are occasionally found in a fossil state. When the tunnel was carried through Highgate Hill, in 1811, concretionary lumps of a brittle substance were discovered, which proved, upon analysis, to be the resin of a coniferous tree changed by mineralization. In a bed of fossil wood, near Hythe, in Kent, a resin was found that partook of the properties of amber and retinasphalt; it was of a clear red colour, very infusible, and acted upon with difficulty by many chemical solvents.[156] [156] Geological Proceedings, 1843. The pollen of pines or firs occurs in a tertiary deposit at Egra, in Bohemia; this bed is entirely composed of pollen and the frustules of many kinds of diatomaceæ.[157] [157] Described by M. Ehrenberg. [Sidenote: AMBER. FOSSIL PALMS.] _Amber_, so remarkable for its electrical properties, and so largely used for ornamental purposes, is a fossil resin, the product of an extinct species of pine (_Pinus succinifer_), which, though nearly allied to _Pinus abies_, and _P. picea_, is essentially distinct. The Amber in the European markets is principally collected from the shores of the Baltic, between Memel and Konigsberg, being washed out of submerged beds of lignite, and thrown up on the strand by the waves. Amber is occasionally found on the eastern and northern shores of England. The forests of Amber-pines appear to have been situated in the south-eastern part of what is now the bed of the Baltic, in about 55° north latitude, and 37° to 38° east longitude, and were probably destroyed at the commencement of the Drift period.