352 BONES OF LOPHIUS PLSCATORIUS — 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 mayprobably 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 graduall}' 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. 



