ERRA TA. 



On page 49, line 15, for "April, 11 read May. 



On page 122, second line from the bottom, for "30 ," read 50 . 



On page 168, line 29, for "sin $," read cos I. 



On page 151, lines 6 and 24, for "p. 6," read/. 150. 



On page 92, line iS, for "Hornett, 11 read Thornette. 



On page 221, line 14, for "ascending," read according. 



On page 273, line 13, for "Eoscawen," read Webster. 



On page 332, line 7 from the bottom, for "Gibbon, 11 read Gliddon. 



On page 379, last line, for "gennanica," read germanica. 



On page 412, omit "B. lanceolatum," seventh line from the bottom. 



On page 461, fourth line from the bottom, for "Samarancy, 11 read Samara ng. 



On page 505, fifth line, for "Microsterias," x&zAMicrasterias. 



On page 541, line 9, for "Mt. Washington, 11 read White Mountains. 



On page 414, line 11 from the bottom, erase "P. oculata." 



On page 212, line 2, omit "Mt., 11 before Wilton. 



