TO 



PROFESSOR R. E. GRANT, M.D., 



F.R.S., F.K.S.E., F.L.S., F.G.S., F.Z.S., ETC., 



I'ROFESSOB OF COMPARATIVE ANATOMY AND ZOOLOGY IN UNIVERSITY COLLEGE, LONDON. 



ETC., ETC., 



'ris M\\m is 



AV1TH THE MOST SINCERE RESPECT 

 FOR HIS PROFOUND KNOWLEDGE OF NATURAL HISTORY IN GENERAL, 



AND ESPECIALLY FOR THE LUCID AND ABLE MANNER 

 IN WHICH HE LED THE WAY IN THE SAME FIELD OF INVESTIGATION AS THAT 



OF THE PRESENT WORK, 



AND WITH MUCH GRATITUDE FOR THE KIND ADVICE 



AND LIBERAL ASSISTANCE THE AUTHOR HAS RECEIVED FROM HIM 



DURING THE COURSE OF ITS PREPARATION. 



