7. SIBBALBIUS. 173 



the posterior pair are wanting. The first has a bifid articular head, 

 the cleft extending to the depth of 5 inches. It articulates by this 

 with the transverse processes of the seventh cervical and first dorsal. 

 Its extreme length in a straight line is 21"; its breadth at the middle 

 2|-", at the lower end 4i". The second, third, and fourth have short 

 capitular processes, not reaching haKway to the bodies of the ver- 

 tebree. These processes are absent in all the others. The longest 

 rib (the fifth) is 41" in a straight hue, the twelfth is 31", and the 

 thirteenth 30". There are ten chevron bones present. The ster- 

 num is remarkably small for the size of the animal, a transversely 

 elongated lozenge in shape, 4" in antero-posterior and 8" in trans- 

 verse diameter. 



" The scapula is, as usual in the family, much elongated trans- 

 versely, and has a long acromion process. Its length is 14", its 

 breadth 25". The humerus is 10" long ; the radius 18|", and pro- 

 portionately slender. The hand, artificially articulated, is 18" long ; 

 the second- digit has, besides the metacarpal, three bones, the third 

 three bones, the fourth six bones, the fifth three bones. These 

 numbers are probably not correct, as they do not correspond with a 

 natural skeleton of the hand of the same species at Brussels. 



" The upper surface of the orbital plate of the frontal is almost of 

 a rhomboid form. The malars are very thin ; the outer end of the 

 lacrymals forms a thick, projecting, rounded knob. The nasal bones 

 are almost straight across their anterior ends, slightly longer at the 

 middle, and sloping away at the sides ; their upper surface tolerably 

 flat, but raised to a low ridge in the middle towards the anterior 

 end, and slightly hollowed on each side of this. The dimensions of 

 the cranium are given in the Table at p. 180, compared with those of 

 other specimens of the genus. The inferior maxUlaries have low, 

 obtusely triangular coronoid processes. They are articulated too 

 close to the head, and their upper edge rotated too much inwards. 

 This position greatly diminishes their curve as seen from above, and 

 causes their extremity to bend downwards. I was much interested 

 in observing this, as it explains away a great peculiarity in the figure 

 of the whale in the Berlin Museum by Rudolphi (Abhandlungen 

 Acad; Berlin, 1822), in which the same mode of articulating has 

 caused some misconception as to the character and relation of these 

 bones, the more important to be rectified, as this is the only figure 

 extant of the skuU of any member of this genus. 



" There can be little, doubt that this skeleton is identical with 

 the above-mentioned specimen described by Rudolphi; at least, a 

 careful perusal of his description and figure (for I have not seen the 

 skeleton) leaves this impression on my mind. In habitat, age, size, 

 number of vertebrae and ribs, and aU other important osteological 

 characters they agree. There are certainly slight differences in the 

 proportions of the parts of the cranium, but not greater than are found 

 among different individuals of undoubtedly the same species ; and it 

 is possible that even these may arise from inaccuracies on the part 

 of the artist. Some of the evidence also is wanting to make the 

 comparison complete ; for instance, the sternum from the Berlin 



