1901.] SKULLS OF LEMURS AJS^D MONKEYS. 137 



P. geoffroyi. The extra-orbital fossa is encircled entirely by the 

 maxilla. A small intercalar bone {x), in the same position as the 

 one mentioned in P. geoffroyi, is on its way to become soldered 

 to the frontal. 



A second specimen of P. calabarensis (Br. M. Z. D. No. 46.11. 

 10.5) is slightly older than the preceding. There is scarcely any 

 pars orbitalis worth speaking of, the os planum reaching almost 

 the crista posterior. On the right side it is almost completely 

 joined to the lacrymal by synostosis, the suture being preserved 

 only in the medial moiety ; on the left side (text-fig. 32) a process 

 of the maxillary — bounded in front by the lacrymal, behind by the 

 OS planum — forms more than half of the crista posterior (laterally); 

 the medial extremity of this latter is formed by the frontal. So 

 that the lacrymal contributes ouly in a slight measure to the 

 formation of the crista posterior ; it is, however, more developed 

 on the right side. The pars facialis of the lacrymal and its fossa 

 proceed diagonally in an antero-external direction, and are deli- 

 mited by the maxillary, which in front and laterally forms a 

 real crista anterior, the latter being flattened medially, as is the 

 case also in the former specimen. 



Tarshcs. 



The crista post. I. is formed by the lacrymal. The pars orbi- 

 talis I. is much reduced in size ; t\\Q pars facialis Z., bearing the 

 fossa, is for the greater pax-t, in front, entirely encix'cled by the 

 maxilla. A fronto-maxillary suture. The malar remains far 

 behind on the orbital margin, its anterior end being above the 

 anterior termination of m. 2. 



Tarsius spectrum (Br. M. Z.D. No. 90.7.25.1). Teeth moderately 

 worn. — Inside the orbit the os planum closely approaches the 

 crista post., so that there is scarcely any pars orbit, lacr. Laterally 

 from the os planum occurs a fontanelle. Outside the orbit, the 

 maxillary, besides encircling the fossa, advances into the latter on 

 its lateral side. 



Tarsius pliilippinensis, S (Br. M. No. 97.3.1.1). Young speci- 

 men with deciduous dentition in place (text-fig. 35).— Similar to 

 the preceding species, but the lateral part of the pars orbitalis lacr. 

 has a larger extension. 



Tarsius, therefore, on the whole closely resembles the other 

 non-Malagasy Lemurs in the conformation of the lacrymal region. 



Galago. 



The lacrymal is more reduced in size than in any of the 

 Malagasy Lemuridse. The anterior boundary of i\iQ fossa lacry- 

 malis, situated on the cheek, is always provided by the maxilla, 

 which forms the roof of the canalis L, and may also protrude more 

 or less into the fossa. 



The malar may or may not reach the lacrymal. There never 

 occurs a lacrymo-nasal suture. 



