1901,] SKULLS OP LBMUES AND MONKEYS. 147 



in one of them the upper part of the crista anterior is formed bj 

 the lacrymal and maxillary jointly. In one of the four specimens 

 of the same species (Br. M. No. 56 h) the os planum partakes in 

 the formation of the crista posterior. 



Midas. 



Fifteen skulls (PI. XII. figs. 2 & 5).— On the whole similar to 

 Hapale, but the supero-anterior angle of the lacrymal encroaches 

 less upon the cheek ; the fronto-maxillary suture is generally 

 broad, sometimes it is somewhat reduced by the advance of the 

 lacrymal ; but I have not met with a lacryrao-nasal suture. The 

 lacrymal is also otherwise reduced in size; from above, the frontal 

 sends a process into the fossa ; from behind, the os planum 

 encroaches upon the crista posterior (e. g. M. mystax, Br. M. 

 No. 992 rt, M. rufiventer, Br. M. No. 45.4.2.8) (PL XII. fig. 5). 

 In one skull of M. chrysomelas (=3£.Jlavifrons, Br. M. No. 1528a) 

 the crista posterior is chiefly formed by the os planum. 



Ceecopithecid^. 

 Semnopitliecus, 



"With regard to this genus, my material discountenances 

 Gegenbaur's statement, who says that, like in the rest of the family, 

 in Semnopithecus almost the whole of the fossa is encircled by the 

 lacrymal, so that the crista anterior is either entirely supported by 

 this bone, or by the lacrymal in conjunction with the frontal 

 process of the maxillary. And again : " A small portion of the 

 maxillary forms the anterior border of the fossa in Semnopithecus 

 (S. nasicus) " \ 



I have examined the lacrymal region of 93 skulls of Semno- 

 pithecus, with the result that only in four cases the conditions 

 are similar or nearly so as described by Gregenbaur; so that I 

 apprehend that he had no true Semnopithecus at his disposal. In 

 fact the only species mentioned is " S. nasicus,'^ the Nasalis, in 

 which the conditions are somewhat different from those of Semno- 

 pithecus. 



If we except Miopithecits and Bhinopithecus (PI. XI. fig. 8), 

 Semnopithecus is the most anthropoid of the CercopithecidsB with 

 regard to its lacrymal. Not only is the crista anterior supported 

 by the maxilla alone, in 89 out of 93 specimens, but generally the 

 latter bone penetrates also into the fossa, thus throwing back the 

 lacrymal. In several cases the participation of the lacrymal in the 

 formation of the fossa is further restricted by the frontal pene- 

 trating into it from above (e.g., S. pyrrhus, Br.M. No. 55.12.24.11, 

 S. obscurus, Br. M. No. 79.11.21.298, S. priamus, Br. M. 

 No.79.9.5.4) ; but generally the antero-superior angle of the 

 lacrymal advances slightly towards the face (Pi. XII. fig. 8). In 

 four cases only (S. envellus, Br. M. No. 13 ^' & 13 p ; S. cristatus, 



^ Op. fit. p. 175. 



10* 



