1909.] . Annandale : Report on the Batoidei. 53 
No. 
Breadth of teeth of upper 
Number of small teeth. 
Measurements of central tooth. 
jaw . 
Left. 
Right. 
Breadth. 
Length. 
II* 
I9’5 mm. 
0 
3 
i2'5 mm. 
I ‘5 mm. 
12 * 
i8-o ,, 
4 
3 
11-25 ,> 
2-0 ,, 
13 
21-0 ,, 
2 
2 
17’0 .. 
3‘o ,, 
14 
20’0 ,, 
3 
3 
> 
i6-o ,, 
i'75 >, 
The numbers marked with a * refer to the specimens of the variety cornifera, the 
remainder to those of the typical form of the species. 
The measurements printed above show how little reliance can be placed on exact 
relative proportions in diagnosing the species of the Myliobatidæ. Palæontologists 
in particular have attempted to separate the species of Myliobatis and even Aètobatis 
by examining the relative length and breadth of the teeth. Of one species only {M . 
nieuhofii) have I been able to examine a series of adult teeth. The measurements 
speak for themselves. So far as the other Indian representatives of the family are 
concerned, most of the jaws I have examined have been those of immature specimens. 
So far as evidence founded on such specimens goes, however, there is every indica- 
tion that variation is no less wide in the allies of M . nieuhofii than it is in that 
species. 
Myliobatis maculata , Gray and Hardwick. 
This species ina^^ be distinguished from M. nieuhofii by (i) its large size, (2) 
its coloration, (3) the arrangement and nature of its denticles, and (4) the shape of 
the snout. 
(1) The size of the adult appears to be nearly twice that of the adult of M . nieuhofii. 
(2) The young (which are often as large as the adult of the other species') have the 
dorsal surface of a deep bronze or greenish grey colour with rather large bluish 
spots scattered profusely on the posterior part of the disk. These spots are a sign 
of immaturity, although exactly the contrary is the case as regards Aètobatis punc- 
tata. The adult M. maculata has the back of a uniform dark slate-grey. 
(3) The most conspicuous feature of the scaling in this species is a longitudinal band, 
consisting of several closely adjacent rows, of flat denticles situated on the mid-line 
. of the scapular region. The small star-shaped denticles in the skin of the back 
are also as a rule better developed in M . maculata than in M . nieuhofii. 
(4) The snout in M . maculata appears to be decidedly more prominent than it is in 
M. nieuhofii, but this is largely due to the fact that its sides form a more acute 
angle. 
I have seen comparatively few fresh specimens of this s]>ecies, and only one that 
appeared to be an adult. It was taken by the “ Golden Crown ” oft' the Orissa coast, 
