ERRATA. 



Page 288, line 14 from top, for " replenished," read " furnished." 

 Page 341, No. 14, for the locality " Fort Washington, Virginia," read "Fort 

 Washington, Maryland ;" — and the same in the description of Fig. 31, page 343. 

 Page 366, line 7 from bottom, for " nucleus," read " nuclei." 

 Page 369, line 16 from bottom, before "errors" insert "from." 



