ISAAC LEA. 265 



could not be so, or he would have seen it. As soon as he 

 pulled out the drawer, Dr. Lea saw at a glance the identical 

 specimen which Ferussac had described. He took it up and 

 declared this to be it. Both the naturalists were surprised and 

 delighted. . . . Thus Dr. Lea's theory of the genus Acostea, of 

 D'Orbigny, was complete it was a Mulleria" At Vienna he 

 showed the Austrian naturalists some features in their species 

 and specimens which had escaped their eyes. At Berlin he 

 found Humboldt and other distinguished men of science much 

 interested in what was going on in geology in the United 

 States. At a dinner with the Philosophical Club in London, 

 Sir Charles Lyell gave him credit for being the first and only 

 one who had yet observed an air-breathing animal in so ancient 

 a rock as that in which the Sauropus primcevus occurred, and 

 added that the Clepsysaurus P ennsylvanicus was the first discov- 

 ery of bones in the new red sandstone, although a jaw of a 

 similar animal had since been found. Colonel Sabine exhibited 

 a bottle which he supposed had come through Behring Strait 

 from Japan, which Dr. Lea was able to claim as a verification of 

 his theory of a west-to-east Arctic current. 



On his return home in November, 1853, Dr. Lea found an 

 accumulation of correspondence and specimens awaiting his 

 attention that hardly diminished, so incessant were the fresh 

 arrivals, during the remainder of his active life, or for twenty- 

 five years. Among his new Southern and Southwestern corre- 

 spondents was Bishop Elliott, of Georgia, who became greatly 

 interested in the mollusca of that State, and engaged the inter- 

 est of others in the subject and in collecting shells. The scien- 

 tific researches of Dr. Lea were continued, with constant pub- 

 lications, until 1877, when a sudden illness which came upon 

 him in Southern California disabled him from further vigorous 

 work. He still, however, continued to add to his collections 

 and perform such work upon them as his strength would allow. 

 He gave much attention to the microscopic examination of 

 quartz crystals, with drawings and descriptions of the inclu- 

 sions and markings of each, so that Prof. H. Rosenbusch, in 

 his work on the subject, mentioned him as having been the 

 first in America to enter into microscopic mineralogy. He 

 had engaged, since his return from Europe, in other branches 

 of natural history than conchology. The elephant folio 

 edition of the account of the fossil footmarks near Potts- 

 18 



