I 



FOREIGN CORRESPONDENCE. 



123 



The age of tlie Stonesfield fossils, nevertheless, remained for a time 

 an object of doubt, when a new discovery rendered extremely probable 

 the antiquity which their natural position in the earth's crust assigned 

 to them. The discovery in question was made in the Purbeck- 

 beds, which, belonging to the upper Oolitic series, lie between the 

 cretaceous formation and the Stonesfield strata. Fourteen species 

 of mammalia, belonging to eight or nine genera {Spalacotherium, 

 Triconodon, Flagiaulcw, &c.) were found there. 



Such was the state of things when another discovery was added to 

 those of which the authenticity had been so much questioned, and 

 obliged us to place the date of the first appearance of mammalia con- 

 siderably farther back. It was made by M. Plieninger, who found 

 at Stuttgard some minute teeth of a new fossil mammal, a type of a 

 new genus, that of J/icrolestes, which he discovered at the junction of 

 the Triassic and the Liassic strata. Hence, the Microlestes is considerably 

 more ancient than the Stonesfield fossils.'" 



If any doubts still remain, however, concerning this great anti- 

 quity of mammalia, they will perhaps be dissipated by a letter which 

 Mr. Pentland has just addressed to M. Elic de Beaumont. 



"It will be interesting to know," writes ^ir. Pentland,t " that there 

 have just been discovered in the 'Bone-Bed ' of Dundry, near Bristol,:j: 

 which belongs to the superior Triassic beds, some indubitable remains 

 of mammalia belonging to the family of Insectivora, and which Owen 

 is inclined to connect with the genus Microlestes of M. Plieninger, 

 formerly discovered in Germany. It is believed that their true posi- 

 tion is of more ancient date than the Lias, and they are certainly the 

 most ancient fossil mammalia known to paleeontologists."' 



M. Elie de Beaumont observes that one doubt only can prevail con- 

 cerning the geological age of the "Bone-Bed" of Dundry; it is, 

 whether this bone-bed is really part of the Trias, or whether it consti- 

 tutes, on the contrary, the first stratum of the Lias which covers the 

 former. However this may be, the discovery made at Dundry entirely 

 confirms that made at Stuttgard. "Thus it is," says M. Elie de 

 Beaumont, " that the progress of observation, whilst multiplying in 

 so surprising a manner the mammalia of the tertiary formations, 

 shoAvs us that they penetrate, though in much smaller numbers, and 

 of much smaller size, into the secondary strata, where they reach, to 

 say the least, as far as the base of the Jurassic rocks, and where pro- 

 bably they will not stop. These new discoveries of fossil mammals 



* The DromotJieriiim sylvestre of Dr. Emmons is another of these " oldest " 

 mammals ; and two or thi^ee jaws have been obtained from the shales associated 

 with coal-beds in North Carolina, which are certainly of Triassic, and possibly 

 Permian age ! — Ed. Geol. 



+ His letter is here translated from the French. 



t By Mr. Charles Moore, F.G.S., of Bath. See " Silmia, " new edit. p. 514. 

 Su- Roderick Miirchison says these remains were fomid " in an agglomerate which 

 fills the fissures of the carboniferous limestone near Frome, Somersetshire ; " 

 meaning thereby, we believe, what is usually known as " the dolomitic conglo- 

 merate." — Ed. Geol. 



