41 
form of a cone, the two cones being connected in each 
vertebra by the pin-hole notochordal canal (Canalis 
dicentralis). As all these spaces are occupied by the 
“remains ’’ of the notochord, the latter is absolutely con- 
tinuous from one end of the column to the other. 
The following description is based mostly on a large 
specimen of an extreme length of 52cm. In this animal 
the neural spines were inclined as follows: 1, slightly 
forwards; 2, 3, 4, 5, almost upright; 6, shghtly forwards; 
7-13, all shghtly curved (with the convexity forwards) 
and project more or less forwards; 14, largest spine (first 
caudal) and projects slightly backwards; from 1-14 the 
neural spines increase in length; behind 14 they all 
incline backwards, the inclination becoming more and 
more marked as the extremity of the tail is reached, 
and they also decrease in length. With regard to the 
haemal spines (of which the anterior ones are very much 
longer than the corresponding neurals), the first 3 incline 
slightly forwards; 4 1s vertical; 5 looks backwards, and so 
do the remainder, the tendency becoming gradually 
exaggerated behind, and at the same time the spines 
becoming shorter until they are about the same length as 
the neural spines. In the average specimen the posterior 
haemals are slightly longer than the neurals (ep. 
fig. 19). 
In the posterior third of the body the vertebral 
column is situated about half way between its dorsal and 
ventral edges. In front of this region, partly owing to 
the slight upward curve of the column, but principally 
owing to the increased length of the haemal over the 
neural spines, the column is situated markedly nearer the 
dorsal than the ventral edge. In the anterior third it 
begins to bend down again slightly, and this is especially 
noticeable in the first 4 or 5 vertebra, the result being 
