108 PROCEEDINGS OF THE AMERICAN ACADEMY 



On motion of Professor D. Treadwell, the memoir of M. 

 de Haar was referred to a committee, consisting of Profes- 

 sor B. Peirce, Professor Joseph Winlock, and Rev. Thomas 

 Hill. 



Professor Agassiz addressed the Academy on the subject 

 of the Classification of Fishes. He spoke of the unsatisfac- 

 tory character of the systems of different naturalists, growing 

 out of a want of some common fundamental feature, corre- 

 sponding to their greater or less complexity of structure, 

 which should serve as a basis. In regarding the whole series 

 of Vertebrata, Professor Agassiz has been led to consider the 

 structure of the mouth as related to the facial bones in their 

 greater or less development and complexity, as furnishing a 

 hint for the classification of this department of the animal 

 kingdom. Fishes differ widely in the structure of the mouth, 

 and by a careful analysis of this structure he had been led to 

 a general deduction, that those fishes in which there is the 

 fullest development of the facial bones should be placed at 

 the head of the series, as coming nearest to the highest Ver- 

 tebrata, while those at the opposite extreme should be placed 

 last. Arranged by this test, the Ganoids would hold the 

 first rank, and the Myzontes the last ; and so with the inter- 

 mediate families. And he thought that his view would be 

 sustained by a fuller investigation of all the anatomical char- 

 acters of the class ; the greater or less complication and de- 

 velopment of their structure in general being found to con- 

 form to the structure of the face and mouth. Professor 

 Agassiz illustrated his view by a comparison of the anatom- 

 ical structure of these parts, as well as other parts, in the 

 Siluroids, the Loricarians, Sturgeons, Salmon, Sharks, &c. 



Professor Peirce made a communication on the law of the 

 formation of the tails of comets, explaining his own special 

 views on the subject. He also presented, in behalf of Pro- 

 fessor Winlock, a comparison between the American and 

 British Ephemeris of the Moon for 1856, showing much 

 greater accuracy in the American Ephemeris. 



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