14 GEOLOGICAL MEMOIRS. 



which as a whole I regard as nearly representing the Lias, corresponds 

 with the Dolomite of Signor Pasini. 



Above this formation in our Alps we have oolitic beds, alternating 

 to a considerable extent with grey compact limestone ; the latter 

 affords numerous fossils, the characters of which, however, it is diffi- 

 cult to determine, as they are not easily separated from the matrix. 

 These mostly belong to the genera Pholadomya, Gervillia, Isocardia, 

 andiNucida. Pasini has found casts oiNerincea ; and I have observed 

 the Terehratula sphcer'oidalis, which is characteristic of the Lower 

 Oolite, to which formation we must refer this group from its position 

 and its fossils. In my opinion, Pasini' s series of npjier and lowei^ 

 oolitic beds are comprehended in this one group, which represents 

 the etage Bajocien of D'Orbigny. 



Following the series upwards, we perceive that this formation is 

 covered by another compact argillaceous limestone, of a grey colour, 

 and often containing shells. Upon this rests a dark grey marly bed, 

 in which, at Monte Spitz, near Rotzo, fine impressions of plants have 

 long since been found. The Abbe Dal Pozzo * mentions the discovery 

 of these fossil plants in the year 1764, when slabs were quarried from 

 the grey limestone to cover the walls of the churchyard. It is sin- 

 gular that these remains have never been critically examined, although 

 the Abbe Fortisf mentioned them. They escaped the notice of INIar- 

 zari and Maraschini ; and CatuUo and Pasini, when writing on the 

 subject, dismiss them with a few words. Having made several visits 

 to this locality, I have been enabled to collect a considerable number 

 of specimens, to study their position, and to observe how this plant- 

 bed passes under Monte Spitz, is continued above Mezzaselva and 

 Roana, and comes out in a long zone in the lower neighbouring 

 valley of the Assa. 



Having recognized by means of some fossils that the lower group 

 of the oolitic system occurs at some points in the valleys of the Vero- 

 nese, and that there also (Vajo del Paradiso) a bed with vegetable 

 remains rests upon it, I requested Dr. Massalongo to institute a search, 

 and he soon favoured me with some specimens of fossil plants from 

 the beds of the Pernigotti hill, near S. Bartolamio. 



Although the plant-bearing rock of this place differs miueralogi- 

 cally from that at Rotzo, yet it evidently occupies the same geological 

 horizon, and contains some species identical with those of Spitz. 



By working at both places, I collected altogether about 700 speci- 

 mens, representing a flora with the following genera : — 



Equisetites. Cycadites. 



Calamites. Zamites. 



Pecopteris. Otozamites. 



Tseniopteris. Brachyphyllum. 



Sagenopteris. Araucarites. 



I shall soon publish my work on these fossils, with illustrations of 

 all the species, in forty 4to plates. I have noticed the discovery itself 



* Memorie storiche dei Sette-Communi Vicentini. 



t Memoires pour servir a I'liistoire uaturelle de I'ltalie. 



