48 BULLETIN 43, UNITED STATES NATIONAL MUSEUM. 



exposed for a distance slightly in excess of its own width. The sphe- 

 noidal tongue is not deflected from the level of the basisphenoid. The' 

 infraorbital foramen, as a rule, is doubled. The posterior border of 

 the vomer is almost on a level with the posterior edge of the hard 

 palate. The angle of tlie mandible is slightly deflected outward. The 

 lachrymal canal, as seen in the orbit, is exceedingly small and in some 

 examples is apparently absent. In large specimens a rudiment of the 

 postorl)ital process is present and the anterior border of the temj^oral 

 Assure is trenchant. 



Nasal bones without median depression.* The shape of the zygoma 

 is subject to considerable variation ; the depth of the notch on the upper 

 border and the height of the arch midway between the maxillary 

 squamosis processes being inconstant proportions. The styloid pro- 

 cess is relatively of great length and projects into the substance of the 

 tongue. From an average of measurements of three specimens, the 

 following was secured : 



Length 28'""'; length of superior dental series 11'""'; outside measure- 

 ment of the width of the dental arch at the first uj^per molar 13'"'"; 

 width of the base of the cranium at the glenoid region 15'""' ; the length 

 of the face from the postorbital processes 9"^'"; the length of the 

 mandible 18"""; the height of the coronoid process 3""". 



The arrangement of the turbinals in Artibeus is as follows: The 

 ectoturbinal is exceedingly slender and is furnished wjth a fleshy sum- 

 mit, which is convolute outward. Its upi)er portion alone is seen from 

 the median surface. The first endoturbinal is free below but fleshy 

 above. It is produced forward one-half its length beyond the end of 

 the ectoturbinal in the form of a lobule, is acuminate, and possesses, as 

 in Dermanura a small posterior lobe. The second endoturbinal is con- 

 cealed by the third. When the latter is pressed aside at its upper part 

 the small biconvolute plate of the second plate is seen in position. 

 The third endoturbinal possesses a large lobule, which lies ui)on the 

 median surface The lobule is subrounded in form, completely occu- 

 l>ying the upper edge of the plate so that it appears to arise from the 

 cribriform by a pedicle. The fourth endoturbinal presents an exposed 

 plate on the median surface. It is beneath the convex nonperforate 

 space and yields a single large convolution, which is turned outward. 

 Although this plate lies back of the cribriform plate the absence of 

 any connection between it and the vomer would seem to show that the 

 arrangement met with in many mammals is departed from. 



Four examples of immature crania were studied. No. 1 measured 

 14"'"^ long and 9'"'" wide at mastoids. Maxilla articulates Avith the 



*The genera Uroderma, Artibeus, and Dermanura are all characterized by this nega- 

 tive character. lu {'ampyrops a groove-like depression is seen on the dorsum of 

 the face at the, upper two-tliirds of the nasal hones. This peculiarity enables the 

 observer readily to distinguish the crania of Uroderma and Tampyrops, notwith- 

 standing that the denta formuhe are the same. 



