242 [Aug., 1847. 



The Book of the great Sea-Dragons, Ichthyosauri and Plesio- 

 sauri, &c, with 30 plates copied from skeletons in the 

 author's collection of fossil organic remains, (deposited in 

 the British Museum.) By Thomas Hawkins, Esq., F. G. S. 

 Folio. London. 1840. * 



A letter was read from Dr. C. Hering, of Philadelphia, dated 

 July 31, 1847, in reference to a Museum of Natural History 

 in Leipzig, under the direction of Prof. Poppig, and asking 

 on behalf of the latter, whether, and in what mode, certain 

 objects of Natural History of this country could be procured 

 for the same. Referred to the Zoological Committee. 



The following communication was read from Mr. Wm. S. 

 Pease, of N. Y., containing some remarks ->a the localities 

 whence the fossils presented by him this evening were ob- 

 tained : 



" The basin of the Chesapeake and its tributaries, the Patapsco, 

 Gunpowder, and other rivers, drain a vast number of shallow 

 vallies, which have been rendered such by filling up with clay, 

 mostly blue, sometimes variegated, containing stone, iron ore in 

 nodular masses with lignite and sulphuret of Iron. Near Balti- 

 more the ore is very abundant, whilst the pyrites and lignite are 

 predominant lower down. The whole rests upon hornblende rocks. 

 This clay is often intercalated with ferruginous sands and gravel. 

 These gravels often unite and form a hard conglomerate rock, 

 as the " White rocks" in the mouth of Patapsco river. The 

 whole deposit is irregular in thickness, enlarging at some points 

 and thinning off very much in others; varying much also in 

 color and consistency. It is always, however, highly ferruginous in 

 its composition, with one exception, and that in the case of a 

 deep leaden or black colored clay, which, upon calcination, be- 

 comes white. Hayden, in his Geological Essays, speaks of lignite 

 having been found in this strata with shark's teeth, &c, (doubtful.) 

 The fossils accompanying this were found in a thin vein passing 

 through the above clay formation, which enlarges very much near 

 the city of Baltimore, and forms the hill known as Telegraph or 

 Federal Hill, associated with lignite and sulphuret of Iron. Cu- 

 cullias have been found at Bear creek, (emptying into the Patap- 

 sco) 5 or 6 miles from Baltimore, partly composed of earthy 

 blue Phosphate of Iron. They were thrown out of an excavation 

 for a well about 25 feet deep. With these, other fossil traces 



