12 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.61. 



of these fossil tympanies, this bone will not be discussed further. In 

 figure 5 the posterior pedicle has been restored to show its relations 

 with the periotic. However, the posterior pedicle is somewhat 

 shorter than is shown in this figure for it rests against the inferior 

 surface of the apophysis of the periotic and not against the broken 

 base of that process as shown in figure 5. No incus was found with 

 this auditory apparatus. Doran,^^ in his notable memoir on the 

 ossicula auditus, figures the incus of Balaenoptera mysticetus (pi. 

 62, fig. 29), but states that he has neither examined nor found a 

 detailed description of the incus of Megaptera^^ 



\ ' •rj 



Fig. 3. — VENTitAL view of uight periutic of Megafteea miocaena X 1, Cat. Xo. lO-'iOO. 

 U.S.N.M. ; LoMPOc, California. 



A long, slender stapes is present in the fenestra ovalis of the right 

 periotic (fig. 6), which is more slender and relatively longer than 

 that of Balaenoptera physaJus. Xo stapes of Megaptera was avail- 

 able for comjDarison. The base of the stapes is soldered to the fenes- 

 tra ovalis. An effort was made to dislodge this bone for accurate 

 studj^, but this plan Avas given up Avhen it became evident that such 

 a procedure would probabh' result in the breaking or destruction of 

 the stapes. The head of the stapes is oval. The crura are long and 

 fairly straight, while the aperture is smaller than in Balaenoptera 

 physalus^ or B. musculus. 



" Doran, Alban H. G., Morphology of the mamaliaa ossicula auditus, Trans. Linnean 

 Soc. London, ser. 2. vol. 1, pt. 7. pp. 371-497, pie. 58-«4. 

 >«Idem. p. 455. 



