THE publication of the Illustrated Catalogue of the Museum of 

 Comparative Zoology has been undertaken with a threefold 

 object. In the first place, like the catalogues of most institutions of 

 a similar character, it is intended to make the contents of our Museum 

 generally known, and to facilitate our exchanges. In the second place, 

 to be the medium of publication of the novelties received at the 

 Museum, which require to be described and illustrated by diagrams 

 or wood-cuts, or more elaborate plates. Finally, it is hoped that it 

 may be the basis of a systematic revision of such natural groups of 

 the animal kingdom as are most fully represented in our collections, 

 and that it may, as far as possible, present to the scientific world 

 the results of the investigations carried on in the Museum with a 

 view of ascertaining the natural limits of the Faunae at the present 

 time and in past ages, and the genetic relations which may exist 

 between the order of succession of organized beings upon the earth, 

 their mode of growth, and their metamorphoses during their embry- 

 onic life, and the plan and complication of their structure in their 

 adult condition. 



The means for publishing this work have been most liberally granted 

 by the Legislature, at a time when, in a less enlightened assembly, 

 the material cares of the community would have engaged their 

 exclusive attention. 



L. AGASSIZ. 

 CAMBRIDGE, March 28, 1865. 



