140 



DB. C, i. POESTTH MAJOR OK THE 



[Feb. 19, 



Loris. 



Five specimens examined. — The lacrymal appears neither 

 inside the orbit nor on the face. In front of the orbit there is db 

 "fossa," entirely encircled by the maxilla. The crista posterior is 

 also formed chiefly, in one case (Br. M. No. 67 c, leftside) entirely, 

 by two processes of the maxilla, which in the latter instance unite 

 on the orbital margin, above the os planum, and are always 

 continued forwards into the fossa. In most specimens these two 

 processes are separated on the orbital margin by a minute process 

 of the planum, which therefore partakes in the formation of the 

 crista j^osterior. In the anterior part of the fossa — where the 

 latter, being roofed over by the maxilla, has become the canalis — 

 may be seen a thin bone which is either the free termination of 

 the reduced lacrymal, covered by the maxillary in the anterior 

 part of the fossa, or, may be, the termination of the os 



Text-tiff. 40. 



Te\t-fig 41 



Te\t-fig. 42. 



Text-fig. 40. Orbital region of Loris gracilis (Br. M. No. 48.10.31.3), about iiat. 



size. 

 Text-fig. 41. The same of Nycticehm tcmligradus (Br. M. No. 96.11.29.4), about 



nat. size. 

 Text-fig. 42. The same of Loris gracilis (R. Coll. Surg. Lond. No. 290), about | 



nat. size. 



(Lettering as in text -fig. 26.) 



planum. In one specimen (Br. M. No. 67 d) the process of 

 the planum can be traced from the crista posterior forward to 

 the anterior end of the canalis ; in the absence of very young 

 specimens it cannot be decided whether this anterior portion is 

 the much reduced lacrymal united by synostosis with the 

 planum, or the planum itself. In a specimen from the collec- 

 tion of the Royal College of Surgeons (No. 290), the condition 

 displayed on the right side conveys the impression that the 

 thin bony plate, visible in the canalis beneath the maxillary 

 roof, is in fact the lacrymal. On both sides of the skull the 

 planum creeps up on the orbital margin and separates the frontal 

 from the maxillary, the former bone in this specimen partaking 

 medially in the formation of the margin. In front of the os 

 planum, a lateral and a medial process of the maxillary unite 



