OP A CETACEAN FKOM THE BKOCKEN HURST BEDS. 711 



Fig. 3. — Anterior Aspect of Caudal Vertebra of Balaenoptera Juddi, 

 showing the depressed form of the neural arch and sutural sur- 

 face, from which the vertebral epiphysis has come away. 



A tail vertebra of a whale, however, is about the last thing which an 

 anatomist would select to furnish characters for a new genus. I have 

 not thought that attention is more likely to be called to the fossil by 

 thus dealing with it than would be the case by adopting the safer 

 course of shrinking from the responsibility of indicating a genus 

 which could not at present be sustained. 



The centrum has lost its epiphyses (fig. 3) ; each end is hexagonal, 

 and marked with the usual radiating longitudinal rugosities. The 

 centrum is longer at the superior margin, which measures nearly 

 7 centim., than at the inferior margin, where the measurement is 

 6-2 centim. ; so that there is a conspicuous leaning forward of the 

 superior margin of the vertebra (fig. 2). Among vertebrates this cha- 

 racter recalls a characteristic condition of the vertebrae of Pliosaurus. 

 As already remarked, the face of the centrum is hexagonal ; it is 

 10*2 centim. wide, and 8*7 centim. deep. The superior surface of the 

 centrum is short, since the transverse outside measurement of the 

 neural arch is only 4 centim. ; and the width of the base of the cen- 

 trum is probably no more, though its anterior and posterior margins 

 are abraded, so that the exact characters cannot be stated. The lateral 

 surfaces are unequally divided by the transverse processes (fig. 3), 

 the superior pair, 5-3 centim. long, being the longest. Their mar- 

 gins are moderately convex ; the inferior lateral borders were under 

 5 centim. long. The posterior surface of the centrum is broken on 

 the superior, inferior, and left lateral margins. The lateral margins 



