554 B. F. Kingsbury and TT. D. Rood. 



tion of the ear capsule associated with the ontpocketing of the peri- 

 lymphatic space we employ the name Prominentia perilymphatica. 

 Without going into a discussion of homologies, we desigiiate as Os 

 squamosum the Os paraquadratum of Gaui)p, but in the use of other 

 names we adhere to the tenns used by him. The term proton, is used 

 as the equivalent of the German word Anlage. 



We depart from the usages of the preliminary paper^ in substi- 

 tuting Veiia petroso-Iateralis for Ve7ia jugularis interna of which it 

 is a direct continuation, employing the name used by Driiner, like- 

 wise using his term, Musculus ceplialo-dorso-rrmndibularis for Mus- 

 cularis depressor mandibuli. Palatoqimdratum is substituted for 

 Quadratum. 



Acknowledgments. We have received material for study and help- 

 ful criticism from many sources and wish especially to express our 

 indebtedness to Professors Wilder and Gage and Dr. W. A. Hilton of 

 Cornell University, Professor Robert Wiedersheim of the University 

 of Freiburg and Mr. B. G. Smith of Syracuse University. Aside 

 from personal obligations we wi-^h to express our appreciation of the 

 works of Wiedersheim and Gaupp in this field of research. 



Ambystomidae. 



Amhystoma'^ punctatum. Two reasons determined the choice of 

 this form as one of the species in which to work out quite thoroughly 

 the development of the ear region: (a) the ease with which a large 

 number of stages, larval, transforming and adult, could be procured ; 

 (b) its systematic rank as a typical urodele. In all, some forty 

 series were examined and four models prepared. In this way was 

 obtained a complete history of the transformations through which 



^Errata. At this point we desire to correct errors that were allowed to 

 creep into manuscript and proof in the earlier paper : 



(1) p. 83, line 2, Heniidactylum slKuild read Ileniidactylinni. 



(2) p. 83, line 11, 4-G mm. should read 12-14 mm. 



(3) p. 83, line 17, 1888 should read 1879. 



(4) p. 80, line 2, caudal should read dorso-caudal. 



(5) p. 87, line 4, Hemidactylum should read Hemidactylium. 



(6) p. 87, Fig. 4, D.e. should read D.p. — Ductus perilymphaticus. 

 ^The same as Ambystoma according to older usage. 



