1895. 



PBOCEEDINGS OF THE NATIONAL MUSEUM. 



775 



COMPARISOX OF THE CHARACTERS OF THE SKI'LLS OF IMPIIYI.I.A AXl. LKSMOOfS. 

 DiphilUa. DeHmodm. 



Anterior niisal aperture as liijih as 

 wide. 



Distance between anterior ends of the 

 preteinporal crests equal to lenjitli of the 

 convex face-vertex. j 



Nasal bones marked at tlie side by a 

 vessel groove. 



The preteinporal crests do not unite to 

 form sagitta. 



The incisive foramina one-fonrtli the 

 length of the flat hard pahite, which is 

 scarcely narrowed posteriorly. 

 The skull subrounded. 

 The margin of the palate bone beyond 

 hard palate with spine. i 



The fronto-maxillary inlhiiion ccmspic- 

 uous, the entire orbital margin swollen. 



The infraorbital canal simple and 

 opening on the face immediately at 

 orbital rim. 



The zygoma narrow, scarcely high in 

 middle; arch well sprung from the side 

 of the head. 



Coronoid process greatly inclined back- 

 ward, much higher than condyloid proc- 

 ess. 



Length of sigmoid notch scarcely ex- 

 ceeding distance from condyloid process 

 to the angle. 



Masseteric impression on lower jaw ex- 

 tends to the free margin of tlie mandible. 



The symphysal suture of the lower jaw 

 closed. 



Within cranium, ethmoid region and 

 body of sphenoid flat. 



Inner wall of orbit nniforndy concave 



Anterior nasal aperture higher than 

 wide. 



Distance between anterior ends of the 

 pretemporal crests greater than that of 

 tlio length of the concave face-vertex. 



Nasal bones without groove, but with 

 four foramina at naso-frontal suture. 



The pretemporal crests unite to form a 

 small sagitta. 



The incisive foramina over one-third 

 the length of the acutely vaulted hard 

 palate, which is narrowed posteriorly. 

 The skull subpyramidal. 

 The margin of the palate bone beyond 

 hard palate without si)ine. 



The fronto-maxillary inflation iiicon- 

 spicuorrs. 



The infraorbital canal double and 

 opening a distance beyond the orbital 

 rim in a depression caused by a thicken- 

 ing of the alveolar border. 



The zygoma wide, conspicuously high 

 at the middle: arch scarcely at all sprung 

 from the head. 



Coronoid proce.ss almost vertical, 

 almost on level with conilyloid process. 



Length of sigmoid notch twice the 

 distance between the condyloid ]iroces8 

 j and the angle. 

 1 Masseteric imjjressiou docs not reach 



the lower margin of the mandible. 

 j Symphysal suture of lower jaw o])en. 



Within cranium, ethmoid region and 

 body of sphenoid greatly elevated. 



Inner wall of orbit convex over region 

 of ethmoid bone. 



The face axis in the two forms beiui;- of the same length, and the eth- 

 moid being wider and deeper in Desmoihis, yvhWe the nasals and naso- 

 maxillary inflations are hirger in Diphylla, gives the impression that 

 the nses of the nasal chambers must differ in the two forms. 

 Measurements of skulls of Diphylla and Desmodus. 



Mcaaurenients. 



T'iphylla Desmodus 

 No. 6990, No. 13202, 

 U.S.N.M. U.S.N.M. 



Greatest length 



Greatest -iviilth 



Least width 



Length of face from orbit 



Length of nasal bones 



Length of palate ■ • ;_ : ' " : ' ',■ 



Width of Tiicsnpterygoid fossa jjosti^norlj 



msUan^e fro.rtiil'o" coronoid to the basal liiu- of ramus 

 Intergouial distance 



2:! 

 U 



8 



3 1 



4 



6 



4 

 14 



4 



10 



