Brooks — The Osteology and Arthrology of the Haddock. 185 



surface slopes backwards, outwards, and slightly upwards. The 

 parapophyses are long, curved, thin plates of bone, which incline 

 downwards and backwards, the tips having a slight inclination 

 inwards. On their upper surfaces a ridge runs from the centrum 

 for about half their length. The lower part of their posterior 

 borders are folded over, as if hemmed. On this posterior border, 

 near the tip, is seen a slight groove for the neck of the rib, and 

 nearly half way to the body of the vertebra a little pit for the head 

 of the epipleural spine. 



The first three vertebrae are so peculiar, as to require separate 

 description. In the others we notice the following differences : — . 

 Following the transverse processes towards the tail, the inclination 

 is more backwards, and the size slightly diminished ; the " hem " 

 at the posterior border becomes unrolled, and the anterior border 

 approximates to it, so that the parapophysis takes the form of an 

 inverted gutter, and in the posterior vertebrae lacks altogether the 

 pit for the epipleural spine. Following them forwards, the inclina- 

 tion in the fourth vertebra (PL YIII., fig. 19) is directly outwards ; 

 the processes diminish rapidly in size, being very short in the fourth 

 vertebra ; the epipleural pit and the notch for the rib approach 

 one another, and become confluent at the sixth vertebra. The 

 groove for the aorta inclines towards the middle line in front, and 

 is nearly median at the fourth vertebra. Followed backwards, it 

 also inclines to the middle line, becoming median about the four- 

 teenth, and behind this it becomes indistinct. The first three 

 vertebrae have no parapophyses, and the posterior zygapophyses 

 have the articular surfaces looking directly upwards (which condi- 

 tion is seen to a less extent in the fourth, fifth, and sixth). Those 

 of the atlas and of the second vertebra are large and prominent. 

 The neurapophyses of the first and second have distinctly less 

 inclination backwards than that of the third or any of the others. 

 The bodies of these three are very short, scarcely more than half 

 the length of the ninth. 



The atlas (PL YIIL, fig. 20) presents a strong neural spine, 

 which is closely connected by ligamentous fibres to the crest of the 

 occipital bone. The neurapophyses expand below into anterior 

 zygapophyses, which are longer and stronger than those of the 

 other vertebrae. These articulate with the upper surface of the 

 articular processes of the exoccipital bone (PL YI., fig. 6, 3). Im- 



