352 BONES OF LOPHIUS PISCATORIUS — MORROW. 
trum is about the same length as the twelfth, and the twenty- 
ninth is double the length of any other centrum. 
The neurapophyses and neural spines. The processes rising from 
the atlas and supporting the supraoccipital may probably be looked 
upon as modified neurapophyses ; those of the axis and third cen- 
trum at their inferior extremities having a greater space between 
them as these centra are wider than the others, the remaining neu- 
rapophyses conforming to the centra to which they are attached. 
The neural spines rise in height gradually from the axis to the 
ninth centrum, slightly fall at the tenth, maintain their height 
to the fourteenth, and diminish gradually to the twenty-first ; 
the twenty-second and twenty-third meet with somewhat round- 
ed points; the twenty-fourth, fifth, sixth and seventh are again 
slightly prolonged, but the structure of their posterior extremi- 
ties is much like that of their centra. The posterior edge of the 
twenty-seventh centrum shows slight increase in median diame- 
ter, but the form of the twenty-eighth centrum is different from 
that of the others, it is marked by a prominence on its median 
line at each side, and at its posterior extremity the neural spine 
overlaps the twenty-ninth centrum for about one-half of its 
length. The twenty-ninth centrum has, extending for nearly 
two-thirds of its length from its anterior edge, on each side, a 
broad wing-like process beginning below the prominences 
on the twenty-eighth centrum, slightly rounded at its outer edge 
and drooping a little towards its posterior extremity ; near its 
superior posterior extremity this centrum is rounded somewhat 
and flattened, and at its extremity, it is transverse to the vertical 
line: the termination of this centrum which supports the caudal 
fin is vertically narrow and perpendicular to the ‘column. The 
neural spine appears in this centrum to be represented by an 
intercalated curved bone, the centre of which lies just posterior 
to a line drawn through the posterior edge of the anterior third 
of the centrum, and there are two foramina at the base of the 
neural canal, below the anterior extremity of the intercalated 
bone. 
The two centra twenty-eight and twenty-nine, appear to be 
the analogues of the sacrum. 
