Geology and Mineralogy. 491 



The question arises whether there i 

 error in the manner of observing or in the instruments. 

 ing the dark line F of Sirius with the hydrogen line B.fi of a Geiss- 

 ler tube, he got always the same result — a shortening of the 

 Sirius line occurs (contrary to Huggins) when the telescope was 

 carried along by the clock-work, and the assistant was at the 

 seeker to keep it on a fixed point corresponding to the slit of the 

 spectroscope ; but if the clock-work stopped, or the assistant de- 

 ranged the position of the star, the light line was displaced and 

 came into coincidence with the star line. Dispensing with clock- 

 work the line was found to be on one side or the other, according 

 as the star was looked at on one side or the other of the axis of 

 the telescope. A change was also noticed on turning the spectro- 

 scope 180° on its axis. No attempt is made to explain these 

 phenomena, but they are pointed out as possible sources of illusion. 

 ~ Comptes Hendus, Ixxxiii, 76 1 , 8 12 / Nature^ xiii, 480. >j. c. p. 



II. Geology and Moekalogy. 



1. Paleozoic fossils from a limestone associated with the Ser- 

 pentine formation (Zone of the Fietre verdi) of Ghaberton (Alpi 

 Cozie).—Prol B. Gastaldi, in the Bulletin of the R. Comitate Geol. 



paper. An accompanying geological section, by Michelotti, 

 gives the stratification of the upper part of Mt. Chaberton: No. 

 1, the dolomitie limestone; 2, anthracitic sandstone of a red 

 color, with black beds containing lamellar hematite, etc. ; 3, 

 quartzyte, with beds of gypsum ; 4, talcose " calcischist," of a 

 greenish color. Michelotti states that in an amphitheater under the 

 summit of the mountain, bounded by lofty walls of dolomitie lime- 

 stone, regularly stratified, presenting splendid examples of folding, 

 he found in fragments of the limestone, among some detritus of 

 serpentine, various limestone blocks that were fossiliferous. The 

 fossils were not as well preserved as could be desired, owing ap- 

 parently to incipient alteration, but they enabled him to distin- 

 guish the following genera : Syringopora, near S. abdita, (a tine 

 species with the long branches one-sixth to one-third of an inch in 

 diameter, and one-eighth to one-fourth of an inch apart, according 

 to the figure) ; Jffalysites ; a branching coral supposed to be a 

 Favosites ; a joint of a stem of an Actinocrimis ; a shell of an 

 Ostracoid, referred to ^^ Cythereis f and a sponge, Lithospongia. 

 The species indicate that the limestone is probably of the age of 

 the later Upper Silurian, or the earlier Devonian. 



Prof. Gastaldi remarks that the limestone beds are superim- 

 posed directly on the serpentine, euphotide, and variolite of the 

 region, in sotne places with a rather sudden transition from one to 

 the other; but also that at other localities the more recent beds of 

 ihepietre verdi zone, that is, the ''Calcischist^' containing beds of 



