MUSEUM OF COMPARATIVE ZOOLOGY. 1G3 



Fif . 4. Tlie cncranial surface of the ethmoid hone of the horse. The dotted line, as 

 it extends across tlie surface, represents the lower limit of the platt; of 

 bone described in the text as covering in the eetoturbinal subdivision of 

 the surface. Katural size. 



Fi"-. 5. Frontal section, diagrammatically treated, of the turbinals of the horse. 

 Natural size. 



PLATE III. 



Fig. 1. Encranial surface of the ethmoid bone of the peccarj'. Natural size. 



Fig. 2. The isolated ridge of the first endoturbinal plate. Natural size. 



Fig. 3. Frontal section of turbinals of same, made close to the encranial surface. 



Natural size. 

 Fig. 4. The encranial surface of the ethmoid bone of the liog. 

 Fig. 5. The under nasal surface of the ethmoid bone of the two-toed sloth {Chokc- 



jius didadi/lns). Natural size. 

 Fig. G. The encranial surface of the same. Natural size. 



PLATE IV. 



Fig. 1. The anterior aspect of the ethmoturbinals of the ethmoid bone of the tliree- 



toed sloth [Bradypus tridudylus). 

 Fig. 2. The encranial surface of the same. 



Fig. 3. The ethmoid bone of the common seal (PJioca vitidina). 

 Fig. 4. The encranial surface of the same. 

 Fig. 5. The under surface of the same. 



The fijjures are all of natural size. 



PLATE V. 



Fig. 1. Median sagittal section of nasal damh^r oi Epomoplwrus rjambianus. Slight- 

 ly enlarged. 

 Fig. 2. The same of PhyUodmiia hastatum. 

 Fig. 3. The same of CaniUia hrcvicauda. 

 Fig. 4. The same of Artibcus (slightly distorted). 

 Fig. 5. Dorsal aspect of the turbinals in Carol! ia hrcvicauda. 

 Fig. 6. The sagittal section of nasal chamber of Ptcrodcrma (slightly distorted). 

 Fig. 7. The dorsal aspect of turbinals of Artibcus. 



Figs. 2-7 enlarged one half. 



PLATE YI. 



Fig. 1. A median sagittal section of the nasal chamber of Mcrjaclcrma spasma. 



Fig. 2. The same of Mcrjaclcrma frons. 



Fig. 3. The same of Nydcris Thcbaica. 



Fig. 4. The same of PJiinolophus fcrrum-cquinum. 



Fig. 5. The same of PhyUurhina tridcns. 



Figures enlarged one half. 



