No. 5. — The Ethmoid Bone in the Bats, By Harrison 



Allen, M. D. 



A COMPARISON of the ethmoid bones of the bats, upon which I have 

 been of late engaged, has resulted in defining some interesting points 

 in the anatomy of the organ of smelling in these animals. Awaiting 

 opportunity for framing more elaborate descriptions, I propose formulat- 

 ing an account of the peculiar appearances of the ethmoid in the various 

 families. I may here state, that, in every example I have examined, the 

 detail in the arrangement of the scrolls of the ethmoid bone has yielded 

 characters by which the genera and even the species can be readily 

 determined. 



The genera examined are the following : Pteropus, Epomophorus, 

 RhinolophuSj Phyllorliina^ Megaderma, Nycteris, Antrozous, Plecotus, 

 Corinorhinus, Vesperugo, Vesper us, Scotophilus, Atalapha, Vespertiiio, 

 Nataliis, Miniopterus, Emhallonura, Taphozous, Noctilio, Molossus, 

 Nyctinomus, Chilonycteris, Mormoops, Macrotus, Vampyrus, Schizostoma, 

 Phyllostoma, Carollia, Glossophaga, Artibeus, Vampyrops, Stenoderma, 

 Chiroderma, Sturnira, Brachypkylla, Centurio, and Desmodus. 



The identifications of Dobson (Catalogue of the Chiroptera Br. Mus., 

 1878) have been accepted in framing the above list. 



In all the genera examined, the ethmoid bone is composed of a ver- 

 tical lamella projected from the cribriform plate, to which in most in- 

 stances there is appended an outer (lateral) horizontal scroll. 



(1.) In its simplest form, the vertical plate bears upon its median 

 surface one or more rudimental scrolls. Examples of this variety are 

 seen in the Nycteridoe. In Nycteris^ Rhiiiolophus, Phyllorhina, and 

 Megaderma spasma, the rudimental scrolls are horizontal ; but in Mega- 

 derma frons they are vertical. The outer (lateral) scroll, which is 

 present in Nycteris and Phyllorhina, tends to be directed inward. 



(2.) In the next degree of complexity met with, the vertical lamella 

 resembles the foregoing, but possesses a small lateral scroll, which arises 

 independently from the cribriform plate. The vertical plate retains 

 upon its median aspect two vertical rudimental scrolls. Example, the 

 genus Emhallonura. 



VOL. Vr. — NO. 5. 



