630 
which persists even after it has been bridged by the pars ascendens 
of the palatoquadrate, the foramen praeoticum basicraniale being a 
wholly independent foramen, of secondary origin, that leads from the 
exterior into the trigemino-facialis chamber and not at all directly into 
the cranial cavity proper. The apparent failure on GREIL’s part to 
definitely and distinctly recognize this has led to considerable con- 
fusion, not only in his descriptions but also in the lettering of his 
figures, for the index line that leads to one of these two foramina in 
most cases leads also to the other. Furthermore, there is frequent 
change in the terminology employed, the several terms, foramen 
praeoticum basicraniale, foramen prooticum basicraniale and foramen 
basale apparently all being used indifferently to designate the posterior 
opening of the trigemino-facialis chamber, while, as already stated, 
the terms foramen praeoticum laterale, foramen sphenoticum, foramen 
prooticum laterale and foramen prooticum are all apparently used to 
designate the related primary perforation of the cranial wall. 
The anterior opening of the trigemino-facialis chamber gives pas- 
sage to all the branches of the profundus, trigeminus and lateralis 
trigemini nerves, to the nervus abducens, the arteria temporalis (caro- 
tis externa), and the venae temporalis and pterygoidea; the posterior 
opening giving passage to the rami hyomandibularis and palatinus 
facialis, the arteria temporalis and the vena capitis lateralis, this latter 
vein being the posterior prolongation of the vena pterygoidea doubt- 
less after that vein has received the united venae temporalis and 
cerebri media (p. 1260), though this is not so stated. The venae 
pterygoidea and capitis lateralis together form the jugular vein of 
current descriptions of other fishes, and the fact that this vein traverses 
a primarily extracranial space that lodges the trigemino-facialis gang- 
lionie complex definitely identifies that space as the homologue of 
the trigemino-facialis chamber of my descriptions of other fishes. 
In embryos of stage 48, and according to GREIL exceptionably 
also in stage 47, two narrow bands of cartilage appear, one of which 
separates the anterior opening of the trigemino-facialis chamber into 
dorsal and ventral portions, while the other cuts off a small part of 
the ventral one of those two portions of that foramen. 
The latter one of these two bands is shown in GREIL’s several 
figures as a narrow band that bridges over the nervus abducens as 
that nerve runs forward along the lateral surface of the sphenolateral 
cartilage after having issued from the cranial cavity througth the foramen 
