282 EDWARD PHELPS ALLIS, JR. 
In these embryos the hypophysis lies at the hind end of a large 
fenestra basicranialis, and even projects posteriorly slightly 
beyond and beneath the tip of the notochord. The fenestra 
basicranialis is bounded laterally by cartilages which Greil 
considers of trabecular origin, the parachordal cartilage not 
extending anteriorly beyond the tip of the notochord. A vena 
hypophyseos is said to arise in the neighborhood of the hypoph- 
ysis and to issue from the cranial cavity through a foramen 
sphenolaterale, which lies dorsal to the trabecula and anterior to 
the foramen sphenoticum minus. ‘This vein falls into the vena 
pterygoidea (jugularis), and although it is not said to be con- 
nected with its fellow of the opposite side by a cross-commissural 
vessel, it is certainly the pituitary vein of my descriptions. There 
is no indication, in the figures given, of amembrane separating 
this vein from the cavum cerebrale cranii, but this membrane 
must certainly exist, for it occurs in all other fishes so far 
considered. 
In early embryos the arteria carotis interna is connected 
with its fellow of the opposite side by a cross-commissural ves- 
sel, immediately posterior to the hypophysis and immediately 
ventral to the tip of the notochord, but Greil says this cross- 
commissure has aborted in the oldest embryos examined by him. 
Anterior to this cross-commissure, the artery gives off an arteria 
palatina, which runs forward ventral and mesial to the trabe- 
cula. The artery itself then runs upward mesial to the trabe- 
cula of its side and is distributed mainly to the brain, one branch, 
however, the arteria orbitalis, being sent outward through the 
foramen sphenolaterale with the pituitary vein, and a second 
branch, the arteria ophthalmica sent outward with the ner- 
vus opticus through the foramen opticum. Before passing up- 
ward through the fenestra basicranialis, the internal carotids 
are said to lie between the ventral surface of the chondrocranium 
and the underlying parasphenoid. 
In the adult, the large fenestra basicranialis of the embryo 
is shown entirely closed by cartilage in the median vertical sec- 
tions given by Giinther (’71), Huxley (’76), and Bing (’05), 
and each of these authors shows a deep pituitary fossa with 
