606 EDWARD PHELPS ALLIS, JR. 
hyoideus and mandibularis branches of the nervus facialis are 
not the same in the adults of the two fishes (van Wijhe ’82). 
In all the other teleostoman embryos that Edgeworth ex- 
amined, the sequence of events is said by him (l. ¢., p. 209) to be 
the same as in Acipenser, but, in all these other teleostomans, 
‘‘the VIIth nerve, at first winding round the hyoid bar, subse- 
quently pierces the hyomandibula owing to chrondrification 
spreading round it; the more primitive condition is preserved in 
Acipenser and Polypterus.’’ Here again the fact that the ra- 
mus mandibularis facialis runs outward, anterior to the hyoman- 
dibula, in Polypterus, is apparently overlooked, for if it issued 
primarily posterior to that cartilage, as it does in Acipenser, it 
would evidently have to cut entirely through it in order to ac- 
quire the position it has in the adult. Edgeworth says (p. 207) 
that, according to Rutherford (’09), ‘‘in the brown trout a down- 
growth of no great size, from the periotic capsule at the edge of 
the foramen ovalis, joins with the symplecticum in front of the 
VIIth nerve, and finally unites with the primitive hyomandibula.”’ 
Edgeworth says that in no case did he himself find any such 
downgrowth from the periotic capsule, which rather strikingly 
recalls the fact that he himself describes a downgrowth from the 
periotic capsule in Ceratodus which corresponds to what Kra- 
wetz describes as an upgrowth from the hyal bar in the same 
fish; and here, as there, it seems probable that the two observers 
simply differently interpreted the same phenomena, and that 
both recorded growths simply represent the chondrification of 
an independent cartilaginous element which preéxisted, in situ, 
in tissues that were not sufficiently differentiated in the sections 
of earlier stages to be recognizable. 
If the development of the hyomandibula of the Teleostei, as 
here described by Edgeworth, be compared both with the con- 
ditions found in embryos of Ceratodus and those in the adult of 
Torpedo, it seems certain that the so-called upgrowth of the hyal 
bar said by Edgeworth to pass anterior to the nervus hyomandib- 
ularis facialis is the homologue of the hook-like process of the 
hyomandibula (pharyngohyal) of the adult Torpedo, and hence 
also of the dorsal process of the hyomandibula (pharyngohyal) 
