AUTHOR'S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, MAY 1 
THE MYODOME AND TRIGEMINO-FACIALIS CHAM- 
BER OF FISHES AND THE CORRESPONDING 
CAVITIES IN HIGHER VERTEBRATES 
EDWARD PHELPS ALLIS, JR. 
Menton : Pra nee 
A functional myodome, or so-called eye-muscle canal, is a 
structure peculiar to fishes, and even among them it is limited, 
in the fishes I have examined to Amia and the non-siluroid 
Teleosts. It is such an important organ in those fishes in 
which it is found that it has necessarily received considerable 
attention and various suggestions have been made regarding 
its origin and development. In my work on the Mail-cheeked 
_ Fishes (Allis, ’09) it was discussed at considerable length, and 
I came to the conclusion that it was primarily a subpituitary 
and intramural space which had been secondarily invaded by 
certain of the rectus muscles, entrance to it having been ac- 
quired, on either side, through a foramen that transmitted a 
cross-comimissural vein which drained the pituitary region and 
more particularly the hypophysis. That any part of the de- 
finitive myodome formed part of the cavum cerebrale cranil, 
that any part of it had been excavated by certain of the rectus 
muscles in previously solid portions of the basis cranii, simply 
in order to aquire more favorable points of origin, or that any 
part of it had been enclosed by the growth of bone or cartilage 
developed for that special purpose, I did not believe. I accord- 
ingly did not, at the time my manuscript was sent to press, 
accept Swinnerton’s (02) contention that, in Gasterosteus, the 
anterior portion of the myodome was an actual derivative of the 
cavum cerebrale cranii, while its posterior portion was an extra- 
mural space secondarily enclosed between the basioccipital and 
the underlying parsphenoid. I, however, later received Gaupp’s 
CG5 b) work on Saimo, and when I found that he had arrived 
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