Kinessury, Columella Auris and N. Facialts. 325 
the subsquamosal and the short cartilaginous processes of the 
quadrate. The shifting of the attachment takes place in the 
growth of the adult rather than at the transformation of the 
larva. 
Ampliuma means (51 mm). Through the courtesy of my 
co-worker, Professor H. W. Norris, I am enabled to give here 
the following brief statement of the relations occurring in 
Amphiuma as found by him and verified by myself in his prep- 
arations. This form is interesting because it possesses a con- 
tinuous cartilaginous connection between the quadrate and oper- 
culum, as described by WrepeERsHeEIM,' Hay,” and WINsLow.’* 
This has been spoken of as the columella, and as the stapedial 
process of the quadrate. It evidently, however, represents 
both the columella (stilus columellae) and the primarily cartilag- 
inous process of the quadrate found in Desmognathus. The 
articulation in the specimen upon which this statement of rela- 
tions is based is much closer than it is in Desmognathus, and in 
older specimens undoubtedly, as described, there occurs a 
fusion of the two structures to form one continuous rod _be- 
tween the operculum and the quadratum. In this specimen, 
the stilus is a cartilaginous process of the operculum which is 
itself cartilaginous. The stilus columellae goes forward and 
slightly upward to become applied to the thickened ventral 
border of the squamosum to which it is joined by connective 
tissue. It is succeeded by the cartilaginous columellar process 
of the quadrate to which it is very closely connected. This 
process lies also against the ventral edge of the squaamosum and 
slightly on its inner side. The connection of the stilus, there- 
fore, is with the squamosum and the cartilaginous process of 
the quadrate and not at all with the ossification which (from the 
condition in the adult Desmognathus and Spelerpes) I have 
spoken of as the subsquamosal process of the os quadratum. 
NOp-cit-,, p. 502. 
2°90, Hay, O. P. The Skeletal Anatomy of Amphiuma during its earlier 
Stages. Journ. Morph., Vol. IV. 
5’98, WinsLow, G. M. The Chondrocranium in the Ichthyopsida. 7 fts 
College Studies, No. 5, 1898. 
