334 H. W. NORRIS 
But the condition in Necturus, and in Siren, is to be regarded as 
secondary rather than primitive. 
The origin of the palatine and alveolar rami of the facial nerve 
by a common trunk is a condition so unique that we seek in vain 
elsewhere in the vertebrate series for a corresponding formation. 
It is certainly far removed from any primitive condition. 
The presence of motor fibers in the palatinus caudalis, appar- 
ently innervating a rudimentary ceratohyoidean muscle, is so 
unusual as to provoke little but skeptical comment. Until more 
and very careful comparative studies are made it seems useless to 
speculate regarding the significance of such fibers and their vestig- 
ial muscle. 
The apparent occurrence of a general cutaneous constituent in 
the facial nerve roots also suggests that it is possibly more gener- 
ally present in other Urodela, but because of its minuteness and 
close association with other components has hitherto escaped 
notice. Its presence is best explained on the ground of a per- 
sistence of a primitive and at one time more fully developed 
characteristic of the facial nerve.. . 
The peculiar relations of the ramus supratemporalis X (IX?) 
to the glossopharyngeal ganglion, and its development of a dis- 
tinct ganglionic mass of its own suggest that we have here in Siren 
a condition closely bordering on that seen in selachians and ga- 
noids where the ninth nerve is described as having a lateral line 
constituent. If it be permissible to speak of 4 lateral line portion 
of the facial nerve, and of the vagus nerve, rather than of a lateral 
line complex the parts of which are distributed peripherally with 
these nerves, then we may consider the ramus supratemporalis © 
as a part of the ninth nerve in Siren. But, as Allis (97) has shown 
in Amia, the ramus supratemporalis IX arises internally from the 
main lateral line tract of the trunk series of neuromasts. In the 
text of this paper the writer has treated the supratemporalis 
in Siren as a ramus of the vagus nerve. 
The structure and connections of the ramus communicans vagi 
cum faciali in Siren are such as to warrant the conclusion pre- 
viously expressed by the writer regarding this nervein Amphiuma, 
