332 MR. W. K. PARKER ON THE OSTEOLOGY OF BAL^NICEPS REX. 



extent, the rest are rather shorter, and are about the same length as the spine of the last 

 cervical. These spines gradually increase in height, the first being one-fourth, and the 

 last half an inch high. The upper ridge of the spine is the longest part ; it is bifurcate 

 behind and sometimes in front. The spines are thickest below, and thicker at their 

 posterior than at their anterior margin. Their shape is oblong, the last being nearly- 

 square, but pitched, as it were, obliquely forwards. The anterior and posterior edges 

 are rough for the attachment of the elastic ligament. The dorsal vertebrae are 1| inch 

 wide across the strong thick diapophyses (PL LXVI. fig. 7), the last being the widest by 

 a line or two ; the diapophyses are widest in the first and narrowest in the last dorsal. 

 These latter processes rise a little as they pass out from the neural arch ; they are concave 

 in outline in front and very arcuate behind, the terminal third being extended in the an- 

 tero-posterior direction, and is on an average more than half an inch broad at this part. 



The terminal part of the diapophysis is bevelled downwards, becomes narrow again, 

 and just beneath its tip forms the flat oblique articular surface for the ' tubercle ' of the 

 rib. The diapophyses are very broad where they are one with the neural arch, and at 

 this part in front each diapophysis has two or three large pneumatic foramina, and there 

 is another large one on each side higher up at the junction of the diapophysis with the 

 neural spine. The large oblique zygapophyses are much like those in the lower cervicals, 

 but they gradually become smaller and nearer together as we pass backwards. Beneath 

 each pre- and post-zygapophysis there is a large rounded, smooth, crescentic notch, 

 which is formed into a foramen by the corresponding notch in the contiguous vertebra ; 

 this foramen is for the exit of the spinal nerves. These round notches have much the 

 same character from the axis to the pelvis ; they are formed at the expense of the strong 

 vertical neurapophyses, which elements dilate above into the zygapophyses, and below 

 into the expanded part which becomes confluent with the centrum. A large space, 

 between the zygapophyses, of the spinal canal is left unprotected by bone. The arch 

 formed by the confluent neurapophyses has a large crescentic notch both before and 

 behind in the upper cervical vertebrae and in the dorsals, being smallest in the dorsal 

 region. But in many of the middle cervicals the emargination between the post-zyga- 

 pophyses is very large and triangular. These upper inter-laminar spaces are filled up 

 in the fresh state by strong interosseous membrane. The spinal canal, very wide in the 

 lower cervical region, becomes narrower in the dorsal, expands very much in the middle 

 part of the sacrum, to narrow more and more down to the last caudal. The ribs are 

 relatively inferior in strength to those of the more robust, thick-bodied Adjutant; the 

 second dorsal rib is strongest and has a medium width of a quarter of an inch. Only the 

 four true dorsal ribs have appendages (PI. LXVI. fig. 1 ap), the longest of which on the 

 second rib is less than an inch in length. The cupped short parapophyses that receive 

 the rounded head of each rib rise higher, as we pass backwards ; those of the last two 

 dorsals being at the upper margin of the centrums. 



The bodies (centrums) of the dorsals are more like those of the Storks than those of 



