374 DR. ST. GEORGE MIVART ON THE SKELETON OE [May 7, 



iu L. JJavo^mlliatus both these margins run iudistinguishably one 

 into the other in one continuous curve. 



In both species the ventral margin of the quadrate is convex in 

 both directions, corresponding with the elongated articular groove 

 of the mandible. 



A second articular surface' for the mandible (one which articu- 

 lates with the inner surface of the articular process of the latter) is 

 situated on the hinder part of the external surface of the quadrate 

 behind and below the externally extending zygomatic process. 

 This surface is strongly concave from without inwards and slightly 

 convex in the opposite direction. The anterior margin of the 

 quadrate has a short, anteriorly concave outline where it joins the 

 pterygoid (^Jt), dorsad of M'hich is a very sharp-pointed process 

 (the orbital process) extending forwards, inwards, and somewhat 

 downwards from just below and in front of the base of the ascending 

 process (see, iu h'g. 1, the process ascending above the hinder end 

 of the zygoma, and, in fig. 2, above that of the pterygoid). 



The zygoma, though nearly straight in both species, is slightly 

 more bent concave dorsally for about its middle third in L. Jlavo- 

 palliatus. It is also, even relatively, somewhat more slender, and 

 does not expand dorso-ventrally where it joins the prosopium 

 nearly as much as in P. erithacus. Apart from this expansion the 

 zygoma is throughout of nearly the same dorso-ventral and trans- 

 verse extent in each species. As before said, the sphenotic process 

 does not so nearly touch the zygoma in L.JJavopalliatus ; yet though 

 it is thus relatively shorter, the lachrymal process approaches it 

 much more nearly, diverging very slightly therefrom as it arches 

 backwards, a little outwards, and subsequently upwards. The 

 distance between its apex and that of the sphenotic pi-ocess is not 

 more than half the distance from the apex of the sphenotic process 

 to the quadrato-zygomatic articulation, while in P. erithacus it 

 nearly equals that distance. 



The lachrymal narrows very gradually to its apex. This 

 narrowing is more gradual in L. Jlavopalliatus^ which also has the 

 apex more truncated aud the dorsal margin of the whole process 

 more strongly concave upwards owing to its greater prolongation 

 postaxiad. 



The outer surface of the cranium in the lachrymal region in front 

 of the orbit is smooth. The lachrymal is very convex dorso-ventrally 

 down to a point nearly opposite the supra-jugular process of the 

 prosopium. Then it becomes concave in that direction in both 

 species, but the concavity is very marked in L. Jlavopalliatus, 

 assuming the form of an antero-posteriorly directed groove, sharply 

 limited above and below. In P. erithacus the same groove exists, 

 but it is very much less marked. Beyond this groove the lachrymal 

 is very slightly convex dorso-ventrally in P. erithacus, while in 

 L. Jlavopalliatus it presents a more decidedly flattened sui'face 

 which looks outwards and somewhat downwards. 



The postero-supci-ior margin of the palatine is, iu both, connected 

 with the basis cranii for rather less than half that margin's extent, 



1 See below, p. 391. 



