36 GEOLOGICAL MEMOIRS. 
the Archegosaurus fully agrees ; which, as the author correctly points 
out, furnishes a proof that representatives of a permanent Larva- 
condition existed among the loricated reptiles of the ancient world, 
im like manner as the sirens (Fischmolge) do among the recent Ba- 
trachians. [J. N.] 
Contributions to the knowledge of VeEiIns (Gangstudien, oder 
Beitriige zur Kenntniss der Erzgiinge, herausgegeben von B. 
Cotra, Heft 1.-—V. WeissENBaAcH, iiber Gangformationen, vor- 
zugsweise Sachsens. Hin Fragment. Freiberg, 1847). 
[From a notice by Dr. von Dechen in the Archiv fiir Mineralogie, vol. xxii. p. 287.] 
Every contribution to our knowledge of mineral veins is welcome, 
both im a scientific and practical point of view ; it is therefore a very 
fortunate circumstance that the Royal Saxon Council of Mines at 
Freiberg have instituted a careful examination of the mineral veins 
in that district, and especially of the causes of their becoming poor 
or rich. These researches are conducted under the direction of a 
committee consisting of MM. Reich, Haupt, V. Warnsdorff, Leseh- 
ner, and Cotta. Its results will, it is to be hoped, be communicated 
in successive numbers of the above work. The above memoir, in- 
complete in consequence of the too early death, in July 1846, of its 
author, Privy Councillor von Weissenbach, has caused the immediate 
issue of this part. 
Herr von Weissenbach is known by the publication in 1836 of 
drawings of remarkable veins in the Saxon Erzgebirge noticed in the 
twelfth volume of the ‘Archiv.’ Since that time, from considerations 
of health, the author had changed his mode of life, and had been com- 
pelled to give up his connexion with practical miming; but this work 
shows that he had not ceased to occupy himself with geognosy, and 
more especially with the origin of veins. 
The term vein-formation has a much less precise meaning than 
that of rock-formation. What constitutes vem-formations in ge- 
neral, how they are to be characterized, and how far they are essen- 
tially to be distinguished from others, is neither so clear a matter, nor 
one on which there is so general an agreement as in regard to rock- 
formations. A certam degree of caprice and diversity still prevails 
in the use of the term ‘ veim-formation.’ Even if we limit our views 
to mineral veins, as Werner, Von Herder and Freiesleben did, still they 
can only be characterized and distinguished by comprehending in one 
definition the sum of the peculiarities of whole groups of these veins. 
osseous remains from the Warwick and Leamington sandstones agree with each 
other and with the fossil remains of the great Mastodonsaurus Salamandroides of 
the German Keuper in their essentially Batrachian nature.” The Batrachian and 
Sauroid affinities of these animals are further elucidated in the chapter on the 
teeth of the Labyrinthodonts in the same author's ‘ Odontography,’ pp. 195-217. 
“In the extinct family of the Labyrinthodonts, the Batrachian type of organiza- 
tion was modified so as to lead directly from that order to the highest forms of 
reptiles, viz. the loricate Sauria,” p. 217. To these views we believe Professor 
Owen still adheres.—Epir. Geox. Journ, 
ie ie ee 
