236 
JURASSIC FOSSILS OF THE MOSCOW BASIN. 
of the carboniferous series of Russia. In ascending the Moskwa, accompanied by 
that gentleman, to about six versts beyond the city and near to the village of Shela- 
pika, we found its left bank to consist of finely laminated, slightly micaceous, inco- 
herent black shale, occasionally pyritous, and rising to heights of forty to fifty feet 
above the stream. These shales are seen at intervals for six or seven versts along 
the Moskwa. 
Among the prevailing fossils here we could not avoid remarking specimens of the 
same Ammonites virgatus found at Pies on the Volga, at Makarief on theUnja, and 
at Jelatma on the Oka, many of them preserving their shells with a beautiful iri- 
descence, and associated with the same Belemnites as in those localities. With 
these, however, were many other forms, such as Trigonia, Astarte, Modiola, Pec- 
ten, Amphidesma, &c., which we had not collected upon the Volga : some of them 
have been recently described by Dr. Fischer. After crossing a neck of land which 
is peninsulated by the river, the same beds are traceable in its banks under the 
village of Koroshovo, where they are overlaid by hard siliceous grits (d of pre- 
vious section), to which we shall hereafter refer. Near the church or western part 
of this long village, the shales are diversified by large, irregularly formed concretions 
of sandy marlstone, containing very numerous organic bodies, many of which, a 
well as little nacreous Ammonites, preserve their shelly covering and are beauti- 
fully iridescent. In this group Dr. Fischer cites the Terebratula acuta, T. ornitho- 
cephala, and T. digona, with Avicula, Astarte and other shells, among which we 
were very much struck with two forms so closely resembling well-known fossils of 
the greensand formation, viz. Pecten orbicularis and Inoceramus sulcatus, that on the 
spot we believed them really to represent those species '. 
Unwilling as we were to admit lithological composition only, as an evidence 
of the age of a rock, we could not avoid being much influenced by such con- 
siderations, when we saw fossils so closely resembling lower cretaceous types, 
imbedded in sandstone, often of a ferruginous colour, in which green grains and 
the oxide of iron were disseminated, just as in the greensand of Western Europe. 
Some of the overlying courses resemble, indeed, as nearly as possible, the ferru- 
ginous bands of the lower greensand, termed “ clinkers ” in England, whilst be- 
neath them the strata are made up of whitish sand passing into harder grit. 
1 On showing this Pecten to M. A. D'Orbigny, he convinced us that it is distinct from the P. orbicu- 
laris : Dr. Fischer has since published it under the name of P . nummularis. It will be described by 
M. D’Orbigny, together with the other fossils, in Part III. 
