504 ALLIS. [Vou. XII. 
the lips of the opening project downward as two columns, which 
then turn backward and, as large nerve cords or strands, extend 
backward along the upper part of the saccus, lying between the 
upper ends of the venous sinus, and forming the upper wall of 
the central cavity of the structure. Diverticula of this central 
cavity are found along nearly its entire length, extending out- 
ward into the venous sinus. They are short in the anterior 
portion of the organ, but long and much convoluted in the 
posterior portion, where the organ becomes a large glandular 
structure. Into this glandular formation nervous strands or 
fibres extend from the upper, nervous wall of the structure, and 
finally, toward the hind end of the organ, the strands and cen- 
tral cavity become entirely lost in the general tissue. No 
slightest indication of a canal or canals extending into the 
mouth cavity was found, and the organ seems to be devoted 
solely to a glandular secretion destined to supply the central 
cavity of the brain, as Waldschmidt states to be the case in 
Polypterus (No. 126, p. 318). That part of the hypophysis 
shown by him in sections seems, however, to be the saccus of 
Amia, his ‘“feinere Gefiige’”’ indicated by the letter d being 
in part, at least, the nervous portion of the organ. The nerve 
cells shown by Bickford in Calamoichthys (No. 11) seem to 
correspond in position to the blood corpuscles of the venous 
sinus in Amia. In Amia no nerve cells associated with the 
organ could be identified. 
The hypophysis, in the adult (Zy, Fig. 64, Pl. XX XVIII), is 
somewhat heart-shaped, viewed from below, the point of ‘the 
heart directed forward. On the sides it extends upward along 
the sides of the anterior end of the lobus infundibulum, this 
part of the lobus containing the cephalic projection of the cen- 
tral cavity of the brain described by Gage. In the floor of 
this cephalic projection is the median fold found in the base 
of the infundibular cavity in larvae. Canals from the hypophy- 
sis open into the infundibular cavity and into the hypophysis 
nerve strands and fibres are sent from the brain, the nervous 
supply being large and important, as is also that of the glandu- 
lar part of the saccus. 
The vein vo of larvae is found in the adult (vo, Fig. 64, Pl. 
