2 ANNALS OF SCOTTISH NATURAL HISTORY 



in the sea ; after death the back was exactly the colour of 

 " dark blue Welsh slates." Under parts white. The animal 

 was a female. On making subsequent inquiry about the 

 white stripes usually present as a distinguishing character of 

 Risso's Grampus, I was informed that " it had little faint 

 gray streaky marks, i inch in width, and some were long, 

 and some were short," but as Mr. Wright had to prompt his 

 informant on this point, I conclude these marks must have 

 been inconspicuous. When requested by Mr. Wright, the 

 lower jaws were very kindly presented to me by Mr. Blake. 

 Before removing the mass of adherent flesh, I made a close 

 examination of the dentition. Taking the left mandible, I 

 found embedded in the flesh, at the point of the jaw in 

 front of the three mandibular teeth, a couple of very small 

 denticles, so soft as to be scarcely calcified, and quite easily 

 cut through with the knife. They appeared on the surface 

 as roughish points hardly to be seen, but easily felt with the 

 finger. Then behind the three mandibular teeth were at 

 regular intervals two small openings into the gum. These 

 were about the diameter of an ordinary knitting wire. On 

 shaving slices off the gum these openings were seen to widen 

 out into tooth sacs of the calibre of an ordinary lead-pencil, 

 and half an inch deep, and they were quite filled with a very 

 soft, white, pasty substance with no signs whatever of calci- 

 fication, except in the walls of these sacs, which were of 

 tolerably hard cartilaginous matter, harder than the sur- 

 rounding gums. The two front denticles had small, rough, 

 shallow sockets in the bone, but the tooth sacs described 

 had no visible sockets in the bone of the jaw, as was 

 ascertained when the flesh was all removed. The right jaw 

 had the couple of small denticles, the three mandibular 

 teeth, and the two tooth sacs in the same order and position 

 as on the left jaw. The mandibular teeth seemed remark- 

 ably loose in their sockets, and with the finger and thumb 

 could be moved quite easily in any direction, the great depth 

 and width of the sockets when compared with the size of 

 the teeth perhaps accounting for this. Each of them was 

 exactly half an inch above the gums ; when removed from 

 their sockets and cleaned, the front one on each side 

 measured i-- inch in total length, the others were all alike 



