1867.] SENATE— No. 52. 11 



ant for the arrangement of the fossil Mollusks is especially 

 desirable. It has not been possible for me as yet to put in 

 order even the fossil fishes, notwithstanding my own famili- 

 arity with this class. 



Our collection of Kadiates constitutes one of the most 

 remarkable features of our Museum. Taking into considera- 

 tion the fossil as well as the living representatives, I believe no 

 museum is richer in this type. Their arrangement is nearly 

 complete, and had we room for a more complete exhibition of 

 them they would add greatly to the interest and attraction of 

 our public rooms. 



In closing these remarks, it is hardly necessary for me to 

 add that the material results of the scientific exploration of 

 Brazil, from which I have lately returned, have been bodily 

 incorporated in the Museum, and now form one of its most 

 important possessions. This expedition, fitted out with the 

 greatest liberality and foresight by Mr. Nathaniel Thayer, has 

 provided our institution with a vast store of the most valuable 

 specimens from all the classes of the animal kingdom. Allowed 

 to take with me a corps of six assistants, already trained in the 

 work of the Museum, and our party being also strengthened 

 by the addition of six volunteer assistants, I was able to lay 

 out a scheme for a thorough exploration of large tracts of 

 country in Brazil, parts of which had not yet been visited by 

 zoologists. It is but justice to those who have accompanied me 

 to state here what has been their share in the work of the expe- 

 dition. 



One of my principal objects during the whole journey was to 

 secure accurate information concerning the geographical dis- 

 tribution of the aquatic animals throughout the regions we 

 visited. Upon this subject we had little precise knowledge, — 

 even the best known among the fishes, reptiles, &c, of the 

 Brazilian waters being entered in our zoological records simply 

 as living in Brazil, or more generally still as found in South 

 America. As the distribution of species lies at the very foun- 

 dation of the question of their origin, I have aimed at ascer- 

 taining as far as possible what are the areas and limits of their 

 localization. To this end not a specimen has been brought 

 home by our party without a special label attached to it, or to 

 the packages containing a number of specimens, with the name 



