MONHEIM ON CALAMINE AND CALC-SPAR. 65 



the first living in small societies in dry trunks of trees, from which 

 circumstance they may be termed Wood-Ants, whilst the others live 

 for the most part in the earth and under stones, or construct their 

 habitations of little fragments of plants. The former predominate 

 in warm countries, the latter in temperate and cold climates. It is 

 worthy of remark, that nine species of these great Wood- Ants occur 

 at Radoboj and CEningen (the latter having eight and the former four 

 species) . One of these, Formica lignitum, Germar, is very similar to 

 our Formica herculanea, Latr., inhabiting the trunks of the pine 

 and fir, and probably lived in the trunks of the cypress of the ancient 

 CEningen forests. This species is found also in the brown-coal of 

 Bonn. 



The second, F. gravida, corresponds to F. (Ethiops, Latr., that lives 

 in Central Europe. And for the remaining members of this group I 

 cannot find analogous living species. 



With regard to the Ants of the second group, I will mention, that 

 one, F. Thetis^ is similar to F. rufa, v/hich is so plentiful with us in 

 woods, and here constructs great conical heaps of fir-leaves and frag- 

 ments of wood ; another, F. ophthalmica, corresponds to the Black 

 Ant, F, nigra, which is widely spread throughout Europe. 



[T. B. J.] 



Pseudomorphosis of CAi.kMi^'E and CKL.c-svA^Rfro7n the Severtn 

 Mine, in the neighbourhood of Nirm, near Aix-la-Chapelle. 

 By V. MoNHEiM. 



[Verhandl. d. Naturhist. Vereins der Preuss. Rheinlande, 1849, V. p. 33, and 

 Leonhard u. Bronn's Jahrb. f. Miner. 1849, p. 862.] 



In breaking a large piece of blende there was found in the inside a 

 druse-cavity, in which at one spot small, but very regular crystals of 

 galena occurred, also minute crystals of iron pyrites, and many other 

 crystals of a yellowish white colour, which were either combinations 

 of the more obtuse calc-spar-rhombohedron with the six-sided prism, 

 or had besides flat extremities. These crystals were situated on the 

 blende, the iron pyrites, or the galena, and were either quite hollow, 

 or their interior was occupied by innumerable, infinitely small, regular 

 forms of the same substance. 



Their chief constituent was, according to our analysis, carbonate 

 of the oxide of zinc ; but they contained also a large per-centage of 

 the carbonate of the oxydule of iron, some carbonate of lime and car- 

 bonate of magnesia. Amongst these hollow crystals were situated a 

 few, somewhat elevated, white crystals of a similar shape, which were 

 evidently to be regarded as calc-spar. Hence we are warranted in 

 concluding that the above-mentioned hollow crystals must be crystals 

 of calc-spar transformed into zinc-spar (calamine), or, more correctly 

 speaking, iron-zinc-spar. They might have been formed thus : water 

 impregnated with carbonic acid and containing in solution carbonate of 

 the oxide of iron, together with some carbonate of the oxydule of iron 

 and a little carbonate of magnesia, came into contact with the calc- 



