446 Proceedings of the 



tions of which had been made by a highly intelligent and ac- 

 complished naturalist, Mr Robert Heddle, now in Canada; Dr 

 M'Bain said that this formula only agreed with that given by 

 Dr Robert Knox, in his description of the Rorqualus Minor, 

 obtained at Queensferry in February 1834, the skeleton of 

 which is now in the University of Edinburgh. In neither of 

 these examples are the second and third cervical vertebrse 

 united by the spinous process, so that this osteological gene- 

 ric distinction of Dr Gray is not a constant character, and 

 cannot be depended on. It is probable that a closer investi- 

 gation of the structure of the base of the skull might furnish 

 better generic characters for separating these animals, as 

 being more certain and permanent than those derived from 

 adaptive differences, more especially when these latter are 

 founded upon single characters. The atlas, in this specimen, 

 is 2\ inches broader than long. The central hole is half a3 

 high again as broad. The second and third cervical vertebrae 

 are not united together by the upper edge. The second cer- 

 vical vertebra has a broad, much-expanded, lateral process, 

 with a round central hole near the body of the vertebra, reach- 

 ing rather less than half its length. The 3d, 4th, 5th, and 6th 

 cervical vertebrse have two, or upper and lower, lateral proces- 

 ses. The upper nearly equal in length, shorter, narrower, and 

 thinner, than the 2d and 7th. The lower lateral process of the 

 second cervical vertebra, equal in size to the upper, approxi- 

 mating at the ends, and nearly forming a ring, approaching 

 nearest on the right side. The upper and lower lateral pro- 

 cesses of the 3d, 4th, 5th, and 6th cervical vertebrse far apart, 

 the basal portion of the lower becoming shorter, the anterior 

 part pointed upwards, beaked, and increasing in length from 

 3d to 6th. The upper lateral process of the 7th cervical ver- 

 tebra resembles the first dorsal in form, but is smaller; the 

 lower process is reduced to a tubercle. The Prozygapophyses 

 are far apart in the cervical vertebrse, increasing in size from 

 5th, and gradually approaching as they recede backwards 

 along the spinal column. 



Omitting for the present other remarks on the remainicg 

 vertebrse, ribs, and pectoral extremities, before concluding, 

 Dr M'Bain said, it may not be amiss to remind those inte- 



