THE SPERM WHALE IN THE SHETLAND SEAS 7 



belonged to the upper jaw. They varied considerably in 

 size and form ; eight of the smallest teeth were curiously 

 bent, and these, Mr. Anderson states in one of his letters, 

 were found in the upper jaw. Three were attenuated in 

 form, pointed at opposite ends, and varied in length from 

 So to 69 mm. The remaining four were pointed at the 

 crown, but were broadened and flattened at the fang ; 

 the longest of these teeth was 88 mm., the shortest was 

 64 mm., and the broadest part of the fang ranged from 

 22 to 32 mm. in different teeth. In five of these teeth 

 a shallow pulp cavity was present, but in the others it was 

 obliterated by hard dense tooth substances, which was 

 frequently irregularly tuberculated. The crowns in four 

 teeth were pointed at the tip, but in the others the tip 

 was roughened and somewhat jagged. In no specimen was 

 the crown polished or worn, and the presumption is that 

 they had not cut the gum. The bent teeth were most 

 interesting in their form. The largest specimens were 

 curved to about ^ of a circle, the two smaller to about ^ a 

 circle, but owing to a twist in the tooth the tips of the crown 

 and fang were not in the same plane. Several had odonto- 

 matous excrescences on the concave aspect of the tooth, 

 resembling the maxillary tooth figured by Sir W. H. Flower. 

 These teeth were obviously rudimentary and functionless 

 (see Plate). 



The sockets of the teeth were elongated antero- 

 posteriorly. Those which had the largest teeth were 8 

 inches in length and about 3^- inches in greatest breadth. 

 In each alveolus the hinder end was the deepest part, 

 from which it gradually shallowed forward. The fang of 

 the tooth was lodged in the deep posterior end. The 

 teeth in the two halves of the mandible behind the 8th 

 pair were not set directly opposite to each other, and for 

 some distance backwards a tooth on one side was opposite 

 the interval between two teeth on the other side, so that 

 the teeth were not symmetrically arranged ; the dental 

 formula, judging from the alveoli, was 23 in the right and 

 22 in the left half of the mandible. 



In two previous communications which I have made 

 to this Society on the occurrence of the sperm whale in 



