On the Fossil Beaks of four Species of Chimeera. 5 
not one of these supposed fossil beaks could be referred to 
that genus. 
In examining the rich collection in the museum at Leyden, 
a few days ago, with my friend Professor Van Breda, I found 
by the side of a Tetrodon a skeleton of that rare fish the 
Chimera monstrosa, of which I had never before seen the bones, 
and instantly recognised in the upper and lower jaws of this 
animal the object of my long research. The two intermaxillary 
bones of the upper jaw corresponded with the pair of tooth- 
like bones from the Kimmeridge clay, which I had in vain 
compared with the teeth of the Zetrodon; the superior 
maxillary bones corresponded with a second pair of the 
fossil bones from the same clay ; and the lower maxillary of 
the Chimera presented the form of the fossil inferior maxil- 
lary bones of my four different species from the Portland 
stone, Kimmeridge clay, Chalk marl, and Chalk. 
This discovery of the type of each of these new forms of 
fossil bones in the mouth of a living species of Chimera, at 
once clears up all the difficulties of which I have so long been 
seeking the solution, and enables me to announce the exist- 
ence of four fossil species of a genus hitherto unheard of in 
the annals of Paleontology; one in each of the following 
four different formations, namely, the Portland stone, Kim- 
meridge clay, Chalk marl, and Chalk. To that discovered in 
the Portland stone; I propose to give the name of Chimera 
Townsendii ; to that in the Kimmeridge clay, Chimera Eger- 
tonii; to that in the chalk marl, Chimera Agassizit; and to 
that in the chalk, Chimera Mantelliz. 
On my submitting these fossils to Professor Agassiz, he at 
once admitted them to belong to the genus Chimera, a genus 
of which the living individuals are extremely rare, and of 
which he knows not where a single prepared skeleton exists, 
except in the museum at Leyden. 
The only known living species of the genus Chimera is 
widely diffused, and- is usually found pursuing herrings and 
migratory fishes: it lives chiefly in the northern seas, and 
occurs also in the Mediterranean. It is most nearly allied to 
the family of Sharks, and is from two to three feet long. The 
cartilaginous nature of its skeleton explains the reason why 
no other bones of the fossil Chimera have been found, together 
with those that form their very peculiar jaws. The hard horny 
plates which cover these jawbones in the living species, and 
perform the office of teeth, are in none of our fossil specimens 
preserved. ‘The two intermaxillary bones of the upper jaw 
of the Chimera Lgertonii have nearly the hardness of enamel, 
and appear to have had no separable horny covering: the 
