The following is a preliminary communication of the results ohtained by us in a study of the relations and connections of the sound-transinitting apparatus in certain American Urodeles.Since it is in the class Amphibia that a sound-transmitting apparatus first appears, a knowledge of the relations liere is of double value,-in aiding the interpretation of homologies in the lower forms (fishes), and in contributing toward the solution of the difficult questions surrounding the significance of the reptilian coluiiiella and the auditory ossicles of the Mammalia. Furthermore, the functioii of the Amphihian columella is unknown, and as a preliminary to esperiinental work its relations in a large series of forms were ascertained.Gauppl has alreadj-called attention to the apparently different relation that the coluniella has to other structures in Urocleles, which led him to beliere that there were two different connections of this element found in these forms, and later? he restated this opinion. Driiner3 has