A MONOGRAPH OF THE BATS OF NORTH AMERICA. 83 



base may be wide or j^ieatly restricted. After a careful search I re- 

 main of the opinion that the differences iu the form of this uniiiue tooth 

 are not of specific si<!,-nilicance.* 



In the teeth of individuals in whom the teeth are worn it is impossi- 

 ble to note distinctions in the relation of these teeth. 



Skull. — The skull is nearly flat. The mesencephalon measures 3™™. 

 The length of the skull is 14""" to 14^""". The greatest width is 8'""\ and 

 the least width, viz., at proencephalon, is 4"'"'.t The posterior impres- 

 sion of the temporal muscle is barely visible. A small sagittal line is 

 seen over the mesencephalon, but no elevation anywhere. The proen- 

 cephalon is seen at the vertex and is convex on the side. The vertex of the 

 face with a linear groove which extends almost to the anterior nasal 

 aperture. The fronto-maxillary inflation is rudimental and confined to 

 the upper border of the orbit and does not involve the lachrymal region; 

 no tubercle is present over the foramina. The lachrymal foramen is 

 large and placed well in advance of the orbital foramen of the infra- 

 orbital canal. The inner wall of the orbit is faintly convex. The infra- 

 orbital canal is not defined inferiorly and the depression lies in a space 

 between the eminence for the third premolar. The paroccipital process 

 is produced as a si)ine, nearly as long as the occipital condyle, and 

 projects below the level of the mastoid. The coronoid process is higher 

 than the horizontal ramus. The masseter impression is brought well 

 down nearly to the lower border of the horizontal ramus. The angle 

 is produced, slender, and reaches slightly beyond the condyle. It is 

 deflected so as to lie to the outer side thereof. A minute posterior 

 spine is seen at the symphysis. 



The following specimens exhibit some individual variations in the 

 skull. The brain case is markedly elevated above the face. Greatest 

 ^yidth, 7"'"'j least width, 4""". A distinct tubercle overlies the orbital 

 foramina. 



M. G072 X. M. The linear groove not quite reaching the anterior nasal 

 aperture. The temporal impressions are well defined, leaving a convex 

 triangle at the occiput. The upper border of the orbit is rather 

 trenchant, no tubercle is present. 



Pedomorphic forms from Georgia, M. 4380-2 IST. M. A tubercle lies 

 over the orbital foramina; a linear groove reaches the anterior nasal 

 aperture; the sphenoidal tongue does not reacth the tympanic bone. 



The turbinals exhibit the following features : The encranial surface in 

 all essential features 'd,s in Adelonycteris. The single ectoturbinal one- 



* This little tofith ciin not he seen to advautiige iiulcs.s studit'd as a uiicrofscopic 

 objict. It is «>x<cedin<ily ditticult to draw. Mr. von Itcrsoii has done the hest ])os- 

 sihle. At my letiuest Prof. Henry F. Oshorn earefnlly examined this tooth. I hoped 

 that he mifj;ht rccofrnize iu it eharaeters iu conimon Avith those of the teeth to the 

 extinct forms of miero-manuualia; hut he assures ui»; that nothing similar to it has 

 been seen hy him in his speeial studies iu this group. 



flu V, nitidm ciliQlabrum tho greatest width is 6""", the least width, 1""", 



