232 EDWARD PHELPS ALLIS, JR. 
In a 40-mm. specimen of Scorpaena scrofa I now find the recti 
externi and interni as described in my earlier work, but they are 
separated by a membrane, delicate in places but well developed 
in others, which corresponds to the horizontal membrane of 
Scomber and Hyodon and separates the myodome into dorsal 
and ventral compartments. The rectus superior of either side’ 
arises in part from the anterior edge of this membrane and in 
part from the dorsal surface of the parasphenoid at or near the 
line where the lateral edge of the membrane is attached to it, 
this line being marked by a slight longitudinal ridge on the 
dorsal surface of the bone. The rectus inferior of either side 
arises from a median vertical membrane similar to that de- 
scribed in Hyodon and Scomber. 
The internal carotid artery, after traversing its foramen at 
the hind edge of the ascending process of the parasphenoid, 
passes across an internal carotid incisure at the antero- 
ventral corner of the prootic cartilage, as in the adult (Allis, 
09, p. 411), and enters the ventral compartment of the myo- 
dome, its farther course and distribution being as in Secomber. 
The cross-commissure of the efferent pseudobranchial arteries 
traverses the subpituitary portion of the myodome, as in Hyodon 
and Scomber. The pituitary veins anastomose with each other 
in the dorsal compartment of the myodome, but they do not 
there form an important sinus. 
In the adult the ramus palatinus facialis traverses a canal 
in the prootic which begins in the trigemino-facialis recess (pars 
ganglionaris of the trigemino-facialis chamber) and opens on 
the internal surface of the ventral process of the prootic. In 
my 40-mm. embryo this nerve perforates a membranous por- 
tion of the prootic bridge, and, running ventrally between the 
side wall of the dorsal compartment of the:-myodome and the 
lining membrane of that cavity, as in Hyodon and Scomber, 
enters the ventral compartment in the subpituitary region and 
then escapes into the orbit. 
In a 40-mm. specimen of Trigla hirundo the conditions are 
practically as in Secorpaena, excepting that the anterior branch 
of the posterior division of the internal carotid artery is inter- 
