. 958 Storer on the 
from a recent specimen, he would be compelled. to 
conclude there must be more than one species. But, 
as in many other instances, they are probably poor 
copies of each other; those points only being partic- 
ularly attended to, which seem to the copier most 
important. In Pennant's “British Zoology," the . 
whole interval between the commencement and ex- 
tremity of the dorsal fin is occupied by an immense 
number of minute rudiments distinct from each 
Other. While the figure of Strack exhibits but sev- 
enteen prominent rays between the extremities, con- 
nected by a membrane. The anal also, differs much 
in the two figures. In the specimen I have just 
described, it will be remembered that not the slight- 
est rudiment of a ray was distinguishable upon the 
dorsal ridge back of the eighteenth ray, until within 
six inches of the base of the tail. Yarrell figures a 
young specimen, showing that there is but one dor- 
sal fin, which occupies the whole length of the back, 
from the gill-covers to within a short distance of the 
tail. If the reason offered “by Cuvier for the disap- 
pearance of the greaier portion of the dorsal fin be 
true, viz., “the middle of it being worn with age, 
po 
Tek 
gives it the appearance of being double,"—and of 
Yarrell, “ but the portion of the fin intermediate be- 
tween the two ends is so slight that it is easily torn, 
or even entirely worn away by use during life,"— 
if this explanation be correct, it is not a little singu- 
lar, that the appearance of the entire dorsal ridge 
should, in my specimen, have been so uniform: no: 
rays partially worn or broken in the interval between 
the extremities, as we should suppose would be pro- 
aet 
