106 



of the Tetracaulodon, which he had noticed at the last meet- 

 ing. 



He called the attention of the Society to four specimens, which he 

 had placed on the table. 1st. A cast of the lower jaw of the Tetra- 

 caulodon, described by Dr. Godman, and figured in our Transac- 

 tions, Vol. IV. N. S., PI. xxvi. 2d. A fragment of a lower jaw of 

 the same species, belonging to our Cabinet, described Vol. IV. N. S., 

 Trans. PI. xxix. 3d. The portion of a lower jaw of a young Tctra- 

 caulodon, exhibited at the last meeting; and 4th, One similar, from 

 the collection of Mr. Koch, and which he stated he was enabled to 

 submit to the inspection of the members, through the liberality of the 

 owner. 



He called attention to the circumstance, that the alveoli for the 

 tusks in the first and second of these specimens were alike in form, 

 depth and direction, but that there was a marked dissimilarity in these 

 respects between them and those of the third and fourth specimens ; 

 the latter being also like each other. In the two former the alveoli 

 are nearly cylindrical, and extend nearly to the inner table of the 

 chin, leaving at their base merely a thin plate of bone : whilst in the 

 two last the alveoli are conical, and so superficial as to leave a space 

 of nearly two inches between their base and the posterior surface of 

 the chin. 



NOTE. — By an error in the typographical arrangement of the table of lon- 

 gitudes in the last Number, at page 66, a blank has been introduced after 

 " Worcester," in the 24th line, of the 3d and 4th columns. This blank should 

 have been in the first line, after " Boston," and the figures in those columns 

 from the first to the 24th line inclusive, should have stood, each of them, one 

 line below their present place — thus : 



2 | Amherst | 9 | 25 | 72 31 35.85 | +7.36 



