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and acusticum and separating them from the foramen faciale, which 
latter foramen was left exposed in the cranial cavity. 
In each of the three specimens examined, the anterior end of 
the recess was much taller, ventro-dorsally, than the posterior end, 
the lateral wall of the recess thus being triangular in shape. The 
cartilaginous anterior edge of the cerebral opening of the recess was, 
in two of the three specimens, prolonged sufficiently to wholly con- 
ceal, in median views, the orbital opening of the foramen trigeminum, 
but in the third specimen this opening was partly visible from the 
cranial cavity. In Goopny’s figure of this fish (l. ec. Fig. 2) this 
foramen is apparently wholly exposed in the cranial cavity, and it 
is shown as very large and as lying wholly anterior to, and bemg 
wholly independent of, a small fossa in which are the foramina for 
the truncus hyoideo-mandibularis facialis and the nervus acusticus. 
It seems to me however probable that there was in this specimen of _ 
Goopry’s a large depression, not shown or described by him, that 
corresponded strictly to the recess in ıny specimens, and that it was 
overlooked by Goopey. A small and apparently wholly independent 
fossa, strictly similar to that here described by GooDEY, is shown by 
GEGENBAUR in Cestracion, and is there called by that author the 
Meatus auditorius internus (l. c. p. 116). 
The antero-ventral portion of the large acustico-trigemino- 
facialis recess was, in all nıy speeimens, separated from that hind end 
of the pituitary fossa that lodges the pituitary vein by a thin partition 
only of cartilage, and this portion of the recess was completely filled 
by the proximal portion of the rectus externus muscle of the eyeball. 
This portion of the externus muscle traversed the foramen trigeminum 
to reach its surface of origin in the recess, and it was everywhere 
separated from the trigeminus and lateralis nerves by the tough 
connective tissues that envelop those nerves. The foramen trige- 
minum lay close to the pituitary foramen, in a pit common to them 
both at the ventro-posterior corner of the orbit, but no single fiber of 
the muscle was found to enter the pituitary canal. The nervus ab- 
ducens, to reach the externus muscle, perforated the tough lining 
membrane of the cranial cavity at some little distance from the 
ventral edge of the acustico-trigemino-facialis recess, and then ran 
antero-laterally between the membrane and the underlying cartilage 
until it reached the edge of the recess. It did not there, m either 
of the three specimens, perforate the cartilage of the cranial wall. 
