OF THE CHINESE WHITE DOLPHIN. 157 



The arches of all are very similar, and terminate in a very short compressed spine of 

 nearly equal height ha all. In the third this spine can scarcely be said to be developed ; 

 in the seventh it is very slightly larger than in the others, and the lamina? of the arch are 

 slightly broader. The zygapophyses of all are well developed, and accurately coadapted ; 

 the third, fourth, fifth, and sixth have very short superior and inferior transverse pro- 

 cesses on each side. In the third these are united together at their extremities on one 

 side only — in the fourth and fifth on both sides, forming complete rings ; in the sixth 

 they are not united, and the lower process is greatly developed in the antero-posterior 

 direction ; in the seventh vertebra the upper process is alone developed, and the body 

 has on its hinder margin an articular surface for the head of the first rib. 



The dorsal vertebra? generally resemble those of other Dolphins. The bodies of the 

 first four only bear articular surfaces for the attachment of the heads of the ribs. The 

 spines are moderately high, compressed, and broad from before backwards. They 

 increase slightly in length from the first. In the posterior part of the region they have 

 a curve forwards. Distinct contiguous articular surfaces to the arches (zygapophyses) 

 cease after the fourth vertebra. The transverse processes have broad concave articular 

 ends for the tubercles of the ribs ; they gradually increase in length, but the last two 

 disproportionately so. Tubercles (superior accessory processes or metapophyses), which 

 are first seen on the anterior edge of the transverse process of the third dorsal vertebra, 

 increase in size, and rise up, being transferred to the sides of the arch, and form the cha- 

 racteristic " clasping" processes, which are strongly developed in the hinder dorsal region. 



The ten lumbar vertebrae have bodies of nearly equal length, hollowed at the side, 

 and keeled below. The transverse processes are long, flat, broad, and directed nearly 

 horizontally outwards, though the hinder ones are bent down at their extremity, and 

 very rough on their upper surface. The spines are moderately high, broad, and nearly 

 vertical, though curving forwards at their extremities. The clasping processes are less 

 developed at the middle of the region than either before or behind. 



The caudal vertebra? present the usual division into two distinct sets — those in front 

 of, and those contained within the expansion of the tail-lobes. The former are twelve 

 in number ; they have (especially towards the end of the series) compressed, vertically 

 extended, comparatively long bodies. There is one vertebra which may be called 

 transitional (the thirteenth caudal, see figure) ; then follow the nine terminal or fin 

 vertebra?, with depressed, transversely extended, and extremely short bodies. The last 

 vertebra is very small, depressed, and triangular when seen from above. The trans- 

 verse processes of the caudal vertebra? gradually diminish in length to the tenth, where 

 they are mere rough longitudinal ridges : in the eleventh all traces of them have disap- 

 peared. The neural arches cease in the thirteenth. The vertical arterial foramina 

 pierce the sides of the first caudal, and are continued throughout the series to the 

 penultimate. 



There are fourteen pairs of ha?mapophyses (chevron bones), all comparatively short 



