CORRIGENDA ET ADDENDA. 



In the explanation of Plate XXXIII, fig. "2, for " Pleurobronchus" read " Pleurobranchus ;" 

 and for " Heninghaus" read " Hoeninghaus." 



Dr. Buckland has furnished the following : — 



Page 396, line 3. I think it proper to notice that the internal structure of the recent Cycadeae 

 here alluded to, as well as that of their fossil analogues, the Cycadeoideae, was pointed 

 out to me by Mr. Brown in the spring of 1828. 



Page 397, line 23. The expression " these differences," inasmuch as several characters are enu- 

 merated in the preceding paragraph equally belonging to Cycadeae and to the fossils, is not 

 quite correct : for the external position and greater breadth of the laminated circles alone 

 determined Mr. Brown to consider the fossils as belonging to a family probably distinct 

 from Cycadeae. 



Page 397, line 5, for revoluta read circinalis. 



Page 399, line 20, for — " they, however, exhibit no traces of vessels such as radiate from the 

 centre and form the silver grain in more perfect kinds of wood," read — " they, however, 

 differ in the want of medullary rays which so generally exist in dicotyledonous wood." 



