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nus muscle. Such an arrangement seems anomalous and calls for a crit- 
ical examination of the evidence. The writer finds that from the common 
trunk of the rami palatinus et alveolaris facialis there is given off pos- 
teriorly a small nerve, the ramus palatinus posterior of Wilder, which 
contains among its non-medullated fibers some deeply medullated ones. 
Most of the latter pass into a branch that terminates in a small vestigial 
muscle which has its origin on the fascia between the quadrate cartilage 
and the lateral edge of the parasphenoid bbne and its insertion on the 
lateral border of the ceratohyal cartilage. That motor fibers should occur 
in a branch of the alveolar and palatine rami seems so improbable that 
the writer ventures little more than the mere statement of the fact. The 
muscle concerned is certainly not a part of the cerato-hyoideus externus 
muscle. It is, however, without exception present in all the specimens 
examined, but like most vestigial structures varies greatly in the degree 
of its development. In the larval stage, of which the writer has no ma- 
terial, it is doubtless of some functional importance. A search through 
the literature on this subject reveals no mention of a muscle in the 
Urodela similar to this rudimentary one in Siren. Schultze (1892) de- 
scribes in the larva of the anuran Pelobates fuscus a muscle, m. sus- 
pensorio-hyoideus, that has its origin “von der lateralen Randparthie 
der Unterseite des Corpus suspensorii und des dicht hinter dem Corpus 
suspensorii f olgenden Theiles des Suspensoriums, ’ ’ and is inserted on the 
“processus lateralis” of the ceratohyal. In the larval condition of Ran a 
pipiens and R. catesbiana the writer finds a similar muscle innervated 
by a branch of the truncus hyomandibularis facialis. 
LITERATURE CITED. 
Bruner, H. L,., 1901. The smooth facial muscles of Anura and Salaman- 
drina, a contribution to the anatomy and physiology of the respira- 
tory mechanism of the amphibians. Morph. Jahrb., Bd. 29. 
Fischer, J. G., 1864. Anatomische Abhandlungen fiber die Perenni- 
branchiaten und Derotremen. Hamburg. 
Gadow, H., 1901. Amphibia and Reptiles. The Cambridge Natural His- 
tory, vol. VIII. London. 
Hoffmann, C. K., 1878. Amphibien. Bronn’s Klassen und Ordnungen 
des Thier-Reichs, Bd. 6, Abt. 2. Leipzig und Heidelberg. 
Huxley, T. LI., 1878. Amphibia. Ency. Brit,, 9th edit,, New York. 
Norris, H. W., 1908. The cranial nerves of Amphiuma means. Jour. 
Comp. Neurol, and Psych., vol. 18. 
Parker, W. K., 1882. On the structure and development of the skull in 
the Urodeles, Trans. Zool. Soc. London, vol. 11, part 6. 
