Osteology of Porzana Carolina. 5 
pletely sessile. As we find among the skulls of all verte- 
brates, I see that in the specimens of skulls of Porzana at 
my hand, some have the condyle relatively much larger 
than it is in others, while some have the foramen magnum 
decidedly more cordate in outline. In calling attention to 
this fact, I mean to say, that birds form no exception to 
the rule among vertebrates generally, that no two skulls 
of the same species are alike in all particulars, and it is 
Fig. 2. Upper view of skull of Porzana carolina. 
3. Under view of the same. Both the same specimen as Fig. 1., and 
both x 2. Lettering as before; v, vomer; Ma, Maxillary; R, Rostrum. The 
mandible has been removed in each case. 
simply out of the question to present descriptions of details 
in structure that will answer for every specimen, If there 
could be such a thing as a type skull of Porzana, all the 
skulls we could collect and compare with it would be found 
to present differences, not only of the kind I have men- 
tioned, but undoubtedly many others. At the same time 
