22 ON THE STRUCTURE OF EUSTHENOPTERON 
On Plate 15 I have figured various centra from portions of the 
trunk associated with their neural arches. I have never seen 
indications of any interdorsal elements. Fig. 1 shows that these 
arches were produced above into broad, flattened and robust 
spines closely opposed. [ am unable to say anything about the 
haemal spines of the trunk further than that they were smaller 
and more slender and pointed than those of the dorsal side. 
This ends my account of the skeletal structure of Eusthenop- 
teron and I conclude with the hope that students of morphology 
will be interested by the profound and suggestive differences 
separating the Devonic Crossopterygii from even such general- 
ized modern fishes as the Polypterin1. 
