BIOGRAPHICAL SKETCH OF ISAAC LEA, LL. D. XLI 



there if he could get leave of absence for three months from his duties 

 at the College of Surgeons. He very kindly pressed ]Jr. Lea to visit 

 him at Richmond Park, expressed great pleasure at meeting him, and 

 hoped to hear from him when he returned to America. Dr. Lea S4)ent 

 a morning with Mr. Sharpe, the eminent geologist. Among other sub- 

 jects the Sauropus in the Eed Sandstones of Pottsville was fully dis- 

 cussed to Mr. Sharpens satisfaction. The fossils of the ISTew and Old "Red 

 Sandstones were the subject of much conversation, and he told ])r. Lea 

 that '' there was much doubt as to the locality where'Dr. Mantell's Td- 

 ar2)edon elgincnse was, foundJ^ * * * " That the rocks of Elgin wero- 

 absolutely Old Eed Sandstone, but the specimen was found farther 

 north, near the coast where New Eed Sandstones were now believed to 

 exist." He agreed with Professor Harkness " that it was very doubt- 

 ful if the age of the Telarpedon elginense was what was assigned to it," 

 and that he was inclined to a different opinion. If this be the case, the 

 Sauropus will prove to be the oldest air-breathing animal yet found. 

 Mr. Sharpe said he " found it very difficult to assign to its proper age 

 this anthracite coal-field ;" he was "inclined to believe it different from 

 that of the coal-fields of Northumberland and Durham." He states 

 that it was his opinion " that many coal-fields, which had been thought 

 to be of the same age would be found to be different." He showed Dr. 

 Lea a collection of Uniones from the Wealden, one of which was remark- 

 able for an angular umbonial slope somewhat like Margaritana arcula, 

 which Dr. Lea had described. Some of his specimens were purchased 

 at the sale of Dr. Mantell, who, it will be remembered, had died while 

 Dr. Lea was on the continent. Many of these specimens had Dr. Lea's 

 labels, which he had put on the previous year when in London, behav- 

 ing gone over the whole of the collection very carefully. Mr. Sharpe 

 gave him a specimen of Pachyodon, which is a very singular genus, much 

 resembling the Unio, but it comes from salt water. He also kindly 

 gave him some of his papers on the Eed Sandstones. 



Dr. Lea called on his old friend, Charles Stokes, the geologist, whom 

 he found very weak and much exhausted. He reclined upon the sofa and 

 conversed about Dr. Lea's former visits to him, Dr. Buckland, &c. He 

 had in his hand a proof of the impression of a new map of Captain jMc- 

 Clure's discoveries in the northern regions, in which Dr. Lea was much 

 interested, having written a long jiaper on the Northwest Passage many 

 years previously. He expatiated very much on the subject, and agreed 

 with Dr. Lea that it would be useless to pursue the discovery, as further 

 search coald not be likely to benefit any one. Visiting the Museum of 

 Economic Geology agaip, Dr. Lea took some fine specimens of Unionidcc 

 for the Institution. He found Sir Henry De la Beche, with whom he had 

 a long conversation on this family, in which he gave him an account of 

 his divisions of it. Sir Henry expressed himself greatly obliged, and told 

 Dr. Lea he had " listened to an excellent lecture." He entirely agreed 

 with him in the manner of placing the specimens in a grooved slat, and 



