MUSEUM OF COMPARATIVE ZOOLOGY. 163 



Fif. 4. The encranial surface of the ethmoid bone of the horse. The dotted line, as 

 it extends across the surface, rejireseiits the lower limit of the plate of 

 Lone described in the text as covering in the ectoturbinal subdivision of 

 the surface. Natural size. 



Y\". 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 peccary. 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 hog. 

 Fig. 5. The under nasal surface of the ethmoid bone of the two-toed sloth (Cholcc- 



2)us didadiiliis). Natural size. 

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



PLATE IV. 



Fig. 1. The anterior aspect of the etlunoturbinals of the ethmoid boue of the three- 

 toed sloth (Brcahjpus tridadylus). 

 Fig. 2. The encranial surface of the same. 



Fig. 3. The ethmoid bone of the connnon seal [Phoca vitidina). 

 Fig. 4. The encranial surface of the same. 

 Fig. 5. The under surface of the same. 



The figures are all of natural size. 



PLATE V. 



Fig. 1. Median sagittal section of nasal chamber of Epomophorus rjamhiamis. Slight- 

 ly enlarged. 



Fig. 2. The same of Pliyllosfmna hasfafum. 



Fig. 3. Tlie same of t'oroUia hrrvkauda. 



Fig. 4. Tlie same of Artdiciis (slightly distorted). 



Fig. 5. Dorsal aspect of tlie turbinals \\\CaroUia hrcvicauda. 



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



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



Figs. 2-7 enlarged one half. 



PLATE VI. 



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



Fig. 2. Tlie same of Mcgadcrma frons. 



Fig. 3. Tlie same of Nydcris Thehaica. 



Fig. 4. The same of Rhinolnphusfernim-cquinum. 



Fig. 5. The same of Plijllurhina trklcns. 



Figures enlarged one half. 



