380 DR. ST, GEOKGE MITAET ON THE SKELETON OF [May 7, 



the palatines. Into the posterior angle of this triangular space 

 the sphenotic process (sj^h) is seen to project in P. erithacus but 

 hardly in L. Jlavajxdliaius. 



The zygoma arches outwards most at a little behind its antero- 

 posterior middle in both species. 



The preorbital prominence also projects out\^ards beyond the 

 anterior half of the zygoma, and between the latter and the outer 

 margin of that process the lachrymal is seen extending backwards 

 and slightly outwards to about the hinder end of the anterior 

 three-fourths of the zygoma in L. Jiavopalliatus, and to about 

 the hinder end of its first third in P. erithacus. 



The quadrate (5) in the last-named species presents, thus 

 viewed, a roughly triangular surface, with one margin mesiad 

 (postaxiad from the attachment of the pterygoid), another 

 externad and postaxiad, and the third (between the attachments 

 of the zygoma and pterygoid) preaxiad and externad. The last is 

 strongly concave, the second very shghtly so, while the first is 

 nearly straight and forms the inner margin of the elongated convex 

 articular surface for the long articular concavity of the mandible. 



The quadrate of L. Jlavopalliatus only differs in that the second 

 margin is relatively as well as absolutely shorter, the quadrate 

 (as before mentioned) extending so much less backwards behind 

 its attachment to the zygoma. The angle formed by the first and 

 second margins is also much more obtuse than in P. erithacus. 



The hindmost boundary of the ventral aspect of the cranium is, 

 in both species, formed by the lambdoidal ridge. In front of this 

 is the occipital region, bounded anteriorly by the occipital condyle 

 and two lines proceednig thence to the two paroccipital processes. 

 Medianly there is visible a median prominence (which is one 

 running dorsad from the middle of the dorsal margin of the 

 foramen magnum) and a depression on either side of it. The 

 prominence is rather more marked in L. Jlavopalliatus than in 

 P. erithacus. 



The deep cleft between the quadrate and the end of the par- 

 occipital process is absolutely as well as relatively greater in 

 L. jlavopalliatus than in P. erithacus, while the quadrate does not 

 extend backwards so far, and is relatively much more distant from 

 the hinder end of the paroccipital process. 



Just in front of the condyle is a small fossa which is very much 

 more marked in L. jlavopalliatus. In front of this again, in the 

 same species, is a transverse zigzag ridge which bounds postaxially 

 the basi-temporal shield {hts). This ridge has the shape of the 

 letter M vvith extremely wide angles, the median angle being post- 

 axiad and forming the antero-inferior boundary of the small pre- 

 condyloid fossa just mentioned. Each lateral end of the ridge 

 bounds the jugular foramen anteriorly — the vagal foramen opening 

 just above it — and joins a ridge bounding laterally (on the same 

 side) the basi-temporal shield (hts). 



In P. erithacus this transverse ridge is very indistinct and not 

 M-like, and presents four small postaxiad prominences on about 



