THE BATS OF THE GENUS MONOPHYLI.US 37 



Ear. — The ears exactly resemble those of M. redmani except that 

 they are slightly broader and the inner surface of the conch is marked 

 by seven distinct parallel cross ridges. 



j\Iuzzle and cJiin. — Noseleaf smaller than in M. redmani, the up- 

 right portion less tapering at tip, its sides nowhere parallel. Groove 

 in chin apparently narrower and deeper than in M. redmani. 



Membrane., feet and tail as in J/, redmani. 



JFur and color. — Fur similar to that of M. redmani in distribution 

 and quality. Color after nearly forty years' immersion in alcohol, 

 mars brown above, wood brown below. 



Skull. — The skull of Monophyllus clinedaphus is slightly smaller 

 than that of M. red?nani.^ though in general appearance it is not no- 

 ticeably different. In M. clinedaphus the rostrum is slightly narrower 

 anteriorly, and the antorbital foramen is placed further forward, its 

 anterior half lying over the first premolar. The striking differences 

 between the two species are seen in the base of the braincase when the 

 skull is held back down. In AI. clinedaphus the plane of the basioc- 

 cipital and basisphenoid, instead of sloping forward at a faint angle as 

 in the other species of the genus, pitches abruptly forward and down- 

 ward at an angle of 32°. The resulting secondary changes in form of 

 the adjacent parts are noticeable on comparison, though not easy to 

 describe. Presphenoid with ventral surface in two planes, the change 

 from the anterior more ventral level to the posterior more dorsal level 

 taking place abruptly at a point about half way between tip of hamu- 

 lars and line joining posterior molars. The median ridge extends as 

 far back as the anterior (ventral) level only, leaving the posterior level 

 essentially flat. 



Measurements of skull of type: Greatest length 31.8; basal length 

 19.4; basilar length 17.4; zygomatic breadth 9; least interorbital 

 breadth 4 ; mastoid breadth 9 ; greatest breadth of braincase 9 ; fronto- 

 palatal depth (at middle of molar series) 2.4; depth of l^raincase 8; 

 maxillary toothrow (exclusive of incisors) 8; mandible 14; mandi- 

 bular toothrow (exclusive of incisors) 8.4. 



Teeth. — The teeth are slightly smaller than in AI. redmani., but of 

 the same form. 



AIeasure7nents . — For measurements of Afonophyllus clinedaphus 

 see table, page 38. 



Specimens exa?ftined. — One, the type. 



Remarks. — This species is strongly characterized by the form of 

 the presphenoid as well as by the more conspicuous peculiarities of the 

 base of the braincase. It requires no special comparison with the 

 other members of the jrenus. 



