209 



for three or four years, procured all the specimens which I thought 

 would throw any light upon its history. My endeavours would, 

 however, I suspect, have been attended with very little success, if my 

 very kind friend, Mr. Townsend, had not availed himself of his vici- 

 nity to Bradford, and favoured me with such specimens as he consi- 

 dered would be most likely to facilitate my inquiries. 



The vertebral column of this species, at least in such specimens as 

 have come under my observation, does not appear to be marked by any 

 very remarkably distinguishing character. The vertebrae are, indeed, 

 thin, but not so much so as those of the last species ; the articula- 

 tions are particularly nicely fitted, and, in consequence, the whole co- 

 himn has a very neat and elegant appearance, as may be seen in the 

 representation of this part of the animal, Plate XVI. Fig. 1. 



At the superior termination of this column, the vertebra?, for the 

 space of about half an inch, and for about the number of eight or 

 nine, comprised in that space, gradually increase in their diameter, 

 but still retain, very nearly, the same degree of thickness, as may be 

 seen in the specimen, Plate XVI. Fig. 2. 



Beyond this point the vertebrae increase in their diameter much 

 more suddenly, have a much larger central foramen, and acquire more 

 than double their former thickness. These vertebrae are generally 

 about six in number, and occupy about twice the length of the for- 

 mer, Plate XVI. Fig. 7- These, when separated, are found to differ 

 very materially from the preceding vertebrae : their inferior surfaces 

 are concave to a considerable depth, whilst their superior surfaces, so 

 far from possessing a corresponding degree of convexity, are, in gene- 

 ral, but slightly rounded, and are very frequently quite flat, Plate 

 XVI. Fig. 3. Hence, between each of these vertebrae, a central cir- 

 cular space must exist, deeper in its centre than at its margin; its mag- 

 nitude, of course, depending on the degree of disparity existing be- 

 tween the opposed surfaces of the united vertebrae. 



To these succeeds a body of a different form, in which the general 



VOL. II. E E 



