100 



DE. H. r. STANDING ON SUBPOSSIL 



forwardly directed course and then converge at a very obtuse angle, finally forming 

 an acute indentation as they meet each other along the median line (text-fig. 20, A). 



Text-fiff. 20. 



Showing form of nasals of (A) Archceolemur edivardsi and (B) A. platyrrJiinus. 



Oi'Mtal Region. — The orbits of A. edwardsi by their size and position closely 

 resemble those of A. 7naJori, though they are in many cases somewhat more forwardly 

 directed, owing to the more forward position of the orbital process of the frontal. 

 The shape of the orbital contour varies considerably, not only in its general proportions, 

 but in regard to the exact position and direction of the prominent marginal convexity, 

 and at times the absence of such a definite raised rim has made it difficult to estimate 

 the real diameter of the orbit. 



One important and interesting feature of the postorbital bar is the fact that its 

 posterior edge shows a sharp inner blade-like projection, in many cases so thin as to 

 be quite translucent. On some skulls a raised line continues this edge for some 

 distance on the inner frontal wall of the orbit. The probable significance of this 

 feature is explained in the last section of this memoir. 



The lacrymal foramen is more distinctly within the outer margin of the orbit than 

 in the case of A. majori, though this is not due to any material difference in relative 

 position, but to the more definite and prominent development of the anterior margin 

 of the orbital rim. 



Temporal Region. — The zygomatic arch is in general more massive than the 

 corresponding structure in A. majori, though there are great variations in its size and 

 robustness, one skull showing a maxim iim vertical height of over 16 mm. The malar 

 has a great vertical depth below the orbit, a feature which we have seen to be still 

 more accentuated in the skull of Palceopropithecus. The lower margin of the 

 zygomatic process of the malar is directed abruptly upwards, forming an angle of 45° 

 with the horizontal plane. 



The inner contour of the squamosal element of the zygomatic arch is not so evenly 

 curved as in A. majori, its anterior border forming, as seen from above, a straight 

 line 1 cm. long at right angles to the long axis of the skull (Plate XVII.). 



Basilar Region. — The auditory buUse are large and prominent, but show considerable 

 variety in shape, size, and relative position. In one skull a deep cylindrical channel 

 exists between the roughened surface of attachment of the rectus anticus major muscle 



