1905.] OSTEOLOGY OF THE EURYL.EMID.E. 31 



presents an nndoubted resemblance, in some respects, to the 

 aberrant Procnias, in others to the Swallows. 



The following characters will, however, probably suffice : — 

 The beak is of great size, neai-ly as broad as long, and joins the 

 cranium by a more or less perfect nasal hinge ; free lachrymals are 

 wanting, save in Caly2:>to'mena ; palate jegithognathous ; palatines 

 shoi't, broad, wide apai't, and produced backward into prominent 

 spurs ; vomer truncated, much reduced and terminating posteriorly 

 in a pair of slender limbs ; pterygoids and palatines articulating 

 by means of an oblique joint ; maxillo-palatine processes reduced 

 to long slender rods slightly expanding at their termination 

 beneath the vomer ; basipterygoid processes wanting ; postorbital 

 processes obsolete ; squamosal process prominent 



The Occipital Region. 



The foramen magnum is cordiform, its ajDex rising only slightly 

 above the level of the superior margin of the rim of the tympanic 

 cavity. The plane of the foramen inclines downwards rather 

 than backwards, as in the Capitonidae, but not to such an extent 

 as in the Bucconidfe. The base of the foramen is not raised above 

 the level of the basi-cranial axis. The supra-forcmiinal ridge is 

 barely traceable. 



There is no lambdoidal ridge, such as is met with in the 

 Capitonidfe for example, but the cranium above the occipital 

 foramen presents a fairly prominent cerebellar dome, bounded on 

 either side by a subcircular depression (the supraoccij)ital fossa). 

 Above this region the skull rises considerably and presents a 

 gently rounded surface. 



The tympanic wings of the exoccipital are considei'ably developed 

 to form a pair of downwardly directed plates, the processus alw, 

 exoccipitalis inferior, having a convex border and a convex surface 

 with recurved free edge : through these plates the semicircular 

 canals can be faintly traced. 



The Cranicd Roof (PL II.). — The cerebral rises vertically above 

 the cerebellar dome and is of considerable width, being wider than 

 long. In regard to the position of the cerebral with i-elation to the 

 cerebellar dome, the Eur-yla?mid8e agree with the typical Passeres 

 and the Oypseli, and differ from the Capitonidag, for example, 

 wherein the cerebral lies in front of the cerebellar dome. The 

 parietal region is maiked by a modei'ately well-defined temporal 

 depression, the '^ temporal fossa," which, however, does not extend 

 further inwaixls than the outer margin of the supraoccipital fossa. 

 This is a Passerine feature ; in the Coraciif ormes these f ossfe 

 usually meet in the middle line, forming a more or less well- 

 marked sagittal crest. 



The temporal fossse in the Eurylsemidas are mainly responsible 

 for the formation of the well-marked squamosal prominences. 



The interorbital region is marked with a more or less distinct 

 median groove, sometimes with a low ridge. Immediately behind 



