12 



INTRODUCTION. 



§ 2. Measurements. 



At the beginniug of my studies iu the European museums I adopted 

 a series of measureiuents which I applied uniformly to all specimens. 

 ft was uot loug before I ijerceived, however, that certain of them were 

 of less value than others in the discrimination of species. I include 

 them all in the tables iu the hope that they may have value in some 

 other connectiou. 



The measurements are given uniformly in centimeters. The total 

 length of the skull is measured from the center of a line joining the 

 surfaces of the occipital condyles to the extremity of the rostrum. The 

 length of the rostrum is obtained by measuring from the extremity of 

 the same to the center of a line joining the bases of the maxillary 

 notches. The orbital breadth is the distance between the centers 

 (antero-posteriorly) of the margins of the orbits. The temporal fossae 

 being in most cases elliptical, the measurements of their length and 

 breadth are made along their major and minor axes. 



§ 3. Abbreviations. 



There are a number of works upon the BelpMnidce to which I shall have 

 need to refer so frequently in the succeeding pages that I have adopted 

 for convenience certain abbreviations of their titles. These works are 

 as follows: 



Title. 



Abbreviation. 



J. E. Gray. Catalosue of Seals and Whales in the British Museum. 2d 

 cd., Loudon, 8°, ISGU. 



J. E. Gray. Synopsis of the Species of Whales and Dolphins in the Col- 

 Ifotion of the Bviti.sh Museum. Loudon, 4°, 1868. 



J. E. Gray. Sujjplement to the Catalogue of Seals and Whales in the 

 British Museum. London, 8°, 1871. 



Wm. n. Floweij. On the Characters and Divisions of the Family Bel- 

 phinidce. Proceed ing.s, Zoological Society of London, 1883, pp. 406-513. 



Wm. 11. Flower. List of the Specimens of Cetacea in the Zoological De- 

 partment of the British Museum. London, 8°, 1885. 



ScHr.EiiEL. Ahhandhingenausdem Gebiete derZoologieundvergleichen- 

 thMi Anatomie. Leiden, 4°, 1841. 



Van Beneuen et Gervais. Osteographie des C6tac6s vivant et fossiles. 

 P.aris, 4°, 1880. 



P. Fischer. Cetac6s du Sud-Onest de la France. Actes de la Societe 

 Liun6enue de Bordeaux, xxxv, 1881, pp. 5-219, pi. i-viii. 



Catalogue. 



Synopsis. 



Supplement. 



Characters and Divisions. 



List. 



Abhandlungen. 



Osteographie. 



C6tac6s de France. 



