42 MR. W. p. PYCEAFT ON THE [May 2, 



Menuridse and other Passerifoi^m types, owing to lack of material. 

 Sucli a comparison I believe would be valuable. 



So far, the peculiar squamosal of the Euryloemidfe i-esembles 

 most nearly, among the Coraciiformes, that of the Oapitonidre. 

 But the likeness is but general, and seems to point to the Capi- 

 toniform type as being the more primitive. Herein, this element 

 is roughly quadrangular in type, but has the antero-dorsal angle 

 produced into a point, which, however, does not extend on to the 

 frontal. Its mesial border is, indeed, exactly coterminous with the 

 extei'nal lateral border of the parietal. The alisphenoid in this 

 skull is prominent and forms a large triangular block fitting into 

 the deeply concave anterior bordei- of the squamosal on the one 

 hand, and overliung by the postorbital region of the frontal on 

 the other. The postorbital process appears to be formed in part 

 by the alisphenoid, and in part by the frontal. The squamosal 

 takes no part whatever iia its foimation. These I'elations can be 

 seen in the skull of Calorliam/phus. 



The resemblance to the squamosal of the Passeriformes is close, 

 but is of a kind such as to leave little doubt but that this element 

 in the Eurylsemidte is much the more specialised : a fact which is 

 somewhat suri^rising, and is at the same time not without 

 significance. 



Comparing the squamosal of Euryloimua ochromelas with that 

 of the Rook {Corvus frugilegus), it will be found that in the latter 

 this element is of considerable size, conical in form, and rises 

 supei-iorly to overlap the fi'ontal as in Eurylcemiis. The base of 

 this cone is broad, and its postero-internal angle is produced 

 backwai-ds and inwards to form a wedge between the parietal and 

 lateral occipital. 



It is from a squamosal of this type that the squamosal of Eury- 

 Icemus has been derived. This evolution has resulted in a much 

 greater extension of the base mesiad, between the parietal and 

 exoccipital, and in the lateral reduction of the body of the bone so 

 as to transfoi'm the sometime cone into a xiphoid shaft springing 

 from a broad base. These changes will become the more apparent 

 by a reference to fig. 1 «, PI. II. 



The nasal varies considerably in foim in this gi'oup. Unfor- 

 tunately, I have not material at my command which will enable 

 me to make a comparison of the early stages of growth of these 

 several varieties. 



The lachrymal is not yet ossified. 



The 2}remaxilla apparently lacks palatine processes. What appear 

 to be vestiges of these seem i-ather to be ossifications of the mem- 

 brane forming the floor of the anterior region of the nasal chamber. 

 This point can only be solved by a further examination of well- 

 preserved material. 



The maxilla appears to be unusually large in the skull, but the 

 decalcification caused by the formalin in which this specimen was 

 preserved has almost obliterated the premaxillary and quadrato- 

 jugal sutures. 



