PEIMATES PEOM MADAGASCAE. 107 



the skulls of A. edwarclsi, and the facial angle is consequently less steep. The nasals 

 are short and broad (text-fig. 20, B, and PI. XIX. fig. 3), and the upward extension of 

 the premaxilla has a stout and outwardly curved margin. The nasal orifice has here 

 a wide circular form, difierentiating it materially from that observed in all the other 

 skulls of this genus. The postorbital bar is very massive. The external surface is 

 broad and inwardly inclined, so as to form a partial postorbital cZozsoJi (PI. XIX. fig. 2). 

 The orbital margin is distinguished from that of A. edivardsi by being sharply defined 

 on its upper and outer border ; the orbits are thus not only actually smaller, but are 

 more tube-like in form than in either of the other species. The interorbital breadth 

 of the new species is also greater than in either of those previously described. 



The incisors are missing, but their alveoli are not far in advance of the anterior 

 margin of the nasals ; the muzzle has thus a truncated appearance. This feature, in 

 conjunction with the small frontal convexity and absence of prominent sagittal crest, 

 gives to the skull a very diiferent profile from that of either of the other species 

 (compare text-fig. 23, p. 103, with text-fig. 47, A, p. 151). 



Family LEMURID^. 



Subfamily Meqaladapin^. 



Giant subfossil Lemuroids from Madagascar. Skull long and narrow. Brain-case 

 depressed ; brain showing evidence of retrogression. Orbits small and tubular. 

 Muzzle elongated. Zygomata high and strongly developed. Mandible massive. 



Dental formula : '•»; «■ i M^m.3.- m.3 



1. J : c. 1 : pm. 3 : ra. o 



Note. — The Megaladapinse in many essential features so closely resemble the 

 LemuriuEe that it seems unnecessary to rank them as a separate family. 



Genus Megaladapis (Forsyth Major). 



Definition. — Gigantic subfossil Lemuroids from Madagascar. Skull long and narrow, 

 with marked postorbital constriction, vertical occiput, and strongly developed sagittal 

 and lambdoidal crests. Facial portion elongated, with great interorbital breadth and 

 large aerial sinuses. 



Dental formula : '■"= "• i ^ p°'-3: m.3 



1. z: e. 1 : pm. 3 : m. 3 



Note. — Among the fossils found at Ampasambazimba are several skulls of a new 

 species oi Megaladapis to which the name of Megaladapis grandidieri has been given. 

 Before describing the distinctive features of these skulls it may be useful to recall in 

 some detail the main characteristics of the genus which are common to all the species 

 now known. 



All three species agree in having a low flattened brain-case and a long narrow skull. 

 The cerebral convolutions are feebly marked ; there is a notable reduction of the 



yoL. XVIII. — PART II. No. 7. — Ma^, 1908. Q 



