PENTHETOR. 



66( 



for the relativtily distinctly longer brain-case (compare fig. 58 with 

 fig. 48, p. 5SS). Rostrum relatively shorter than in Thoopierus, 

 front of orbit above front (in Thooptenis above back) of p' ; pre- 

 maxillse narrow, in simple contact anteriorly. Maxillary tooth- 

 rows extending considerably behind ventral margin of orbit 

 (('. e. posterior margin of zygomatic process of maxillary), the 

 anterior point of that margin being opposite the anterior third or 

 fourth of m^ (in Cijnopterus and Thoopterus opposite back of m') ; 

 postdental palate somewhat less than one-third of median palatal 

 length (thus shorter than in Cunopterns ; in reality both the bony 

 palate as a whole and that portion of the palate which is situated 

 behind the zygomatic processes are in Penthetor exactly of the same 

 relative length as in Cynopterus, and the shorter postdental palate 

 in the former genus is due only to the tooth-rows extending further 

 backward). Postorbital foramina entirely absent ; foramen 

 rotundum and ovale usually separated (fused in three skulls, 

 97.9.5.2, 9.4.1.62, and 9.4.] .66, of twenty examined). Zygomata 

 thinner than in Ci/nopierits, supraorbital processes shorter, tem- 

 poral ridges sometimes closely approximated but never fused to 

 form a sagittal crest, coronoid process narrow antero-posteriorly, 

 more sloping than in Thoopterus, but scarcely more so than in 

 Cynopterus brachyotis. — As evident from the above and from a 

 comparison of the skull figures 58 and 48, the Penthetor skull 

 differs from that of Cynopterus chiefly by the absence of supra- 

 orbital foramina, the shorter and broader nasals, by having the 

 upper tooth-rows extending further backward, and the foramen 

 ovale and rotundum usually separated ; from that of Thoopterus 

 (which is, however, only imperfectly known) by the rather shorter 

 rostrum and more backwardly extending upper tooth-rows. 



^ 



P* 



Fig. 59. — Eight p3, p-i, ml, and left p.,, p^, m,, viewed from behind, of 



A, Penthetor lucasi (type of species), and 



B, Thoopterus nigrescens (type of species). 



\ (Hnear). 



Dentition (figs. 58, 59). — Dental formula as in Ptenochirus and 



^t iM'cp'p'p^m' ^ _^ 



Metjcerops : — i— i-t--- - x2^28. 



■^ ^ 1. c p, P3 p, m, m^ 



