BIOGEAPHICAL SKETCH OF ISAAC LEA, LL. D. XXVJI 



eter. All the species in tbis formation are new. Von Ilaner called it 

 RaUstatter ScMchten; it is tbe same as that of St. Cassian in the south- 

 ern part of the Alps. He told Dr. Lea that in the Vienna Basin the 

 Miocene and Pliocene were one formation, that they could not make a 

 separation. He also showed him a -fossil Unio which came from the 

 Tertiary of Solsnitz. It was about 4 inches wide and undulate over the 

 posterior i)ortion. The geological survey of the empire was beings 

 made by the members of this institute at the rate of 10,000 square miles 

 a year, and would require thirty years to finish it. It was on an enor- 

 mous scale. 



Dr. Lea was gratified by receiving a call from Professor Bou6, the 

 geologist, who had been a student with his old friend. Professor Van- 

 uxem, in Paris in 1816. He resided some distance in the country, but 

 hearing that Dr. Lea was in Vienna, very kindly came to see him and 

 oftered his services. 



Dr. Lea made other visits to the Imf»erial Geological Museum, and in 

 one of these he saw Professors Homes and Swess. After comparing 

 some fossil shells Professor Swess went with him to the zoological de- 

 partment, where he introduced him to Professor Frauenfeld, and to the 

 distinguished zoologist, Desing, who had unfortunately become blind. 

 They received him with the kindness so characteristic of the Germans. 

 With these professorsDr.Leawentoverthewhole collection of TJnionidce 

 and found mucti that was very interesting, particularly the specimen 

 which he recognized as figured in Wood (Index Testalogicns) as Mya 

 nodvlosa. It was labeled Chama plmnbea by Muhlfeld, but the habitat 

 was not given, which is very much to be regretted, as Wood knew not 

 whence it came. The great interest attached to this mollusk is that it 

 does not belong to the nodulous group of North America Unionida\ 

 By inspecting this specimen, which consists of the right and left valve 

 of two different individuals. Dr. Lea detected the very curious fact that 

 both the teeth (cardinal and lateral) are striate, like the teeth of CastaJia. 

 Neither Wood nor these gentlemen had observed this important char- 

 acteristic which places it in another genus, while exteriorly it is the 

 same as TJnio* Dr. Lea had a long conversation with Professor Swess 

 about the muscles of the Brachiopoda. He and Mr. Davidson of Lon- 

 don did not agree with- Professor Owen on the use of these muscles. 

 He showed Dr. Lea many curious forms of the interior processes of the 

 Terehratula, recent and fossil, and as his paper was soon after published 

 with good figures, the result was exceedingly interesting to malacolo- 

 gists. Dr. Lea showed him the muscles of attachment in the shell of 

 the Unio, and that of the liiiament of the back, for the purpose of giving 

 him some hints as to the probability of finding soniething analogous in 

 the Brachiopoda in reference to the open condition of its valves when at 

 rest, referring also to those genera- which have internal ligaments, viz, 



*Dr. Lea wrote from Vieuna an account of tliis discovery to Dr. Loidy, to be read 

 before the Academy of Natural Sciences. 



