jo Dlßinftive CharaclerL -Tombac brown—metallic yellowifh brown. I-ivcr brown—greyifh brown. In examining the colours of foffiis the interna! is chiefly to be regarded, as the external is oftert ftained or tarniffied, and the furface frequently of a different nature from decompolftion or mixtare with a foreign mineral. Shape. The ffiape of foffiis is either indetcrmlnate, particular, or regulär. Indeterminate, or amorphous, is that which ca» be compared with no other. Partieuhr Shapes. Deniiför'm, fhort, foraewhat crooked, cones. Filiform. Capillary flill finer. Interwovenr, or reticular. , Denritic, or arborefeent. Coralliform, or torked and crooked *. StalatiitiCy cones iffijing from a common fterrr. Fubuliform, flender cylinders adjoining eacto other. Ramißed. Botryoidal, like grapes. Kidneyform, or reniform, round elevations bearing other fmall elevations. Bulbous, prefenting rounded elevations witb ibme depreffions. Deprcjfed, an elevation beat in in the middle *fv * Zackig. ^ Geholfen. Specular^