236 



[January, 1843. 



returning his acknowledgements to the Academy for his elec- 

 tion as a Correspondent. 



The Chairman read a letter from Mr. W. Byrd Powell, 

 dated Little Rock, Arkansas, December 3, 1842, soliciting 

 exchanges, and desiring information on subjects connected 

 with Natural History. 



Also a letter from Professor Locke, of Cincinnati, contain- 

 ing further observations on the subject of the fossil Crypto- 

 lithus tesselatus, described by him in a former communi- 

 cation to the Academy, and published in its Proceedings.* 

 In this letter he states, that since the publication of his 

 paper, he has had an oppor- 

 tunity of examining a large 

 number of specimens, which 

 have enabled him to correct 

 his description in several par- 

 ticulars, viz : " The appear- 

 ance that the shield covered a 

 part of the articulations was 

 accidental ; these articula- 

 tions are six in number, and 

 uncovered by the shield, ex- 

 cepting the outer portion of 

 the anteriorcostal arches, (see 

 figure ) The tail in the most 

 perfect specimen consists also 

 of six articulations, each sub- 

 divided by an inferior joint 

 or depression, giving the ap- 

 pearance of twelve articulations. The middle lobe of the 

 tail is itself trilobate, appearing like the whole body of a 

 small trilobate entire." 



* See Proceedings for July, 1842, pp. 196, 197. 



