PEOFESSOR FLOWER ON THE RECENT ZIPHIOIE WHALES. 225 



first three cervical vertebrae are anchylosed, the next one is more or less free, and the 

 remaining three are anchylosed again." In another specimen of the same genus lately 

 added to the Sydney Museum, the first, second, and third are said to be united and the 

 remainder all free (Krefft, MS.). 



The articular surfaces on the atlas for the occiput (fig. 2) are considerably smaller than 

 in Hyperoodon, and do not coalesce at their inferior margins. Above the upper end of 

 each there is a deep groove for the suboccipital nerve,- instead of a foramen as in 

 Hyperoodon. 



The coalesced spines of the first and second vertebra? are but moderately developed, 

 and slope backwards, overhanging the short pointed spine of the third (see fig. 1). The 

 transverse process of the atlas is very little developed, and placed low on the sides of 

 the bone ; it does not unite at its extremity with that of the axis as in Hyperoodon. 

 The inferior surface of the conjoined bodies of the first three vertebrae has a backward 

 projecting compressed tubercle, wanting in Hyperoodon, and probably representing that 

 so well developed in the Narwhal and Beluga. 



The axis has two very short transverse processes on each side, compressed from before 

 backwards, both placed on the side of the body, the lower one corresponding serially 

 with the transverse process of the atlas, and being of about the same length. 



The third has two distinct transverse processes on each side, further apart than those 

 of the second, the upper one arising from the upper part of the body and root of the 

 arch ; the lower one is longer and narrower, and directed downwards and backwards. 



Each of the three following vertebrae (figs. 3, 4, and 5) have two transverse processes, 

 the upper ones (diapophyses) arising from the pedicle of the arch, rather slender, 

 conical, and inclined downwards, in the sixth also somewhat forwards; they increase 

 in size from the fourth to the sixth. The lower processes (par apophyses) arise from the 

 inferior outer angle of the body, are thick and massive ; that of the fourth vertebra is 

 most compressed and longest, while that of the sixth, though scarcely extending laterally 

 beyond the body of the vertebra, is greatly developed downwards, forwards, and inwards 

 (passing beneath the body of the antecedent vertebra), being, in fact, little more than 

 a great development of the inner basal tubercle of the others, and answering to the 

 41 inferior lamella " of the transverse process of the corresponding vertebra of the 

 Carnivora, Ungulata, &C 1 . 



The seventh vertebra (fig. 6) has only the upper transverse process from the arch, the 

 inferior projecting edge of the well-marked articular surface for the head of the first rib 

 taking the place of the inferior process. 



The bodies of all these vertebrae are broader than they are high. The arches of the 

 fourth and fifth are incomplete in the middle line above for a space of more than half 

 an inch. The arches of the sixth and seventh are complete, and incline backwards, 

 but without any distinct spinous process. 



1 See ' Introduction to the Osteology of Mammalia,' p. 22, 1870. 



