38 BULLETIN 43, UNITED STATES NATIONAL MUSEUM. 



outer semicircular canal free from boue. lu Macrotus this character 

 is less constant than in other genera examined, for out of three exam- 

 ples one showed the loop occupied with a thin, bony lamina. 



Millimeters. 



Length of skull 23 



Width of skull at the widest part 9 



\ Width of dorsi-facial region at the widest i)art 5 



Length of superior dental series 9 



Width of base at the glenoid cavities 11 



- In the skull of an immature individual from the Museum of Compara- 

 tive Zoology, measuring 21'"'" from end of the premaxillato the occiput, 

 the following characters are noted: The mandible projects 2""" beyond 

 the premaxilke. The premaxillie do not join the nasals, which are 

 twice as wide at the posterior ends than at the anterior. The tympanic 

 bones are complete. 



The arrangement of the turbinal plates is as follows: The ectotur- 

 binal is small, a little less than one-half the length of the first eudo- 

 turbinal. Its upper border is horizontal and its lower concave. The 

 extreme tip of the lobule extends as far as the anterior border of the 

 first molar. The second plate is concealed and the third and fourth 

 are arranged much as in Vampyrops, which this form in great part 

 resembles. The lobnle on the first endoturbinal is small, but readily 

 discernible. The i)lates below their inflated summits are not clearly 

 seen. The i^arts on the median surface are contiguous. 



Xotes on the sh'lefon. — The atlas is provided with two spines on the 

 uferior border of the transverse process and a tubercle on the body. 

 The meso-sternum is provided with a trenchant unbroken keel. The 

 i.lnar rudiment at the distal end of the radius is a minute tubercle 

 without notch or foramen; the proximal rudiment is a little less than 

 half the length of the radius. The vertebral border of the scai)ula is 

 sigmoid with the concavity corresponding to the base of the spine. 

 The infra spinatus fossa is not deepened at the axillary border. The 

 end of the sinne at the glenoid cavity eud is not angulated. The 

 coracoid process is abruptly curved toward the axillary border; the 

 end reaches a point below the glenoid cavity. The inner tuberosity 

 of the humerus is scarcely elevated above the level of the head. A 

 uarrow notch is defined between the epitrochlea and the trochlea, the 

 under border of the epitrocldea is fnrnished with a spine. 



The first metacarpal bone eq[ua]s one-half the length of the first 

 phalanx of the first digit, the second lacks one fifth the length of the 

 third metacarpal bone and is slightly arched. The second digit is as 

 long as the third metacarpal bone. The third and fifth metacarpal 

 bones are of equal length and are not as long as the forearm. The 

 fourth is 2'""\ shorter. The third metacarpal bone is much the 

 stoutest, the second phalanx is slightly the longer. In repose the first 

 phalanx of the third digit is in axial line with the third metacarapl 

 bone. The fourth and fifth digits are of the same length. The femurs 



