1881. ] Geclogy and Paleontology. 1023 
the preparations made by Dr. Hahn, 32 photo-lithographic plates 
are given of 142 transparent sections. Dr. Weinland estimates 
that there are fifty various species of polyps, crinoids and alge in 
Dr. Hahn’s preparations. 
“These ‘celestial fossils’ tell us of a planet on which aquatic 
life was sufficiently developed to produce them and to preserve 
them after death by a process of infiltration with siliceous mate- 
rial which dissolved the lime of which their structure must have 
consisted, as far as their inorganic constituents are concerned, and 
supplanted it by the various kinds of siliceous materials, filling up 
also the interstices and openings which had formerly contained 
organic substance. This planet, therefore, must have had a 
comparatively long period of existence; it must have had an 
atmosphere, and its surface must in whole or in part have been 
covered by water. Since bacteria are known to be able to with- 
stand a temperature of 100° C., without losing vitality, the Thom- 
son-Richter hypothesis of the propagation of life through the 
universe becomes almost a tangible reality.” 
It is nevertheless extremely probable that Dr. Hahn and friends 
have been deceived, and a great deal more evidence will be re- 
quired by biologists before crediting these alleged discoveries. 
—Eds. 
new species from the Ticholeptus beds. : 
of the British Association for the Advancement of Science, ‘Dr. 
H. G. Seeley described the characteristics of the Plesiosauroid 
that the genus represents a transition between terrestrial and 
aquatic s, and that the origin of Plesiosaurus from a land rep- 
tile is thus clearly indicated. This reminds us of the Neustosau- 
rus gigondarum of Raspail, described in 1842, which was said to 
have a similar structure, and which, Professor Bronn remarked in 
” 
Lethza Geognostica, “‘ist nicht zu glauben ohne zu sehen!” | 
