354 MR. W. p. PYCRAFT — CONTRIBUTIONS [Apr. 9, 



this family, but in a few genera the reverse is the case, e. g. 

 Myiarchus arundinicola. 



No members of the groups here dealt with have developed a 

 true nasal-hinge, but this is feebly represented among certain 

 Tyrannidfe, e. g. Megarhynchus, Rhynchocyclus, and Conto'pus. 



The Base of the Skull. 



Basipterygoid processes are not even represented by vestiges. 

 The basitemporal plate exhibits the usual triangular form, the 

 base of which is bounded by a more or less well-marked pre- 

 condylar fossa ; while its two sides have fused, for the greater part 

 of their length from the base forwards, with the ossified con- 

 nective tissue forming the anterior wall of the recessus tym- 

 panicus anterior — converting the Eustachian grooves into tubes 

 opening at the apex of the triangle. The posterior angles of this 

 plate contribute to form the inferior margin of the tympanic 

 recess. Although this plate presents certain differences, when a 

 large number of genera belonging to different families are 

 examined, these differences are of too subtle a character to be of 

 any use for systematic purposes. 



The Lateral Aspect of the Cranium. 



The tympanic cavity, as seen in the dried skull, may be described 

 as moderately well developed. In some cases, however, a much 

 more spacious cavity is formed by the extension of the lateral 

 wing of the exoccipital. As a rule, this aperture is oval in shape, 

 but in some cases, e. g. Phytotoma, Vireolanius, Lalage, and 

 Priono2)s, it forms a vertical slit, the distance from the shaft of 

 the quadrate in front to the latei-al exoccipital wing behind 

 being much less than the height of the aperture, whereas, 

 generally, the vertical axis is but little longer than the horizontal. 

 More rarely the free edge of the lateral exoccipital wing is 

 turned sharply forwards and somewhat inwards, so that a large 

 and nearly closed resonant chamber is formed having a sub- 

 crescentic external aperture, as in Paradisea for example. In 

 the Gymnorhinse and in Artamia, one of the " Vangidse," the 

 free edge of the lateral occipital wing, instead of sweeping 

 upwards and forwards so as to pass imperceptibly into the 

 processus articidaris squamosi, is continued upwards till it bisects 

 a ridge running from the squamosal head of the quadrate across 

 the shallow temporal fossa or along its inferior border. This 

 peculiarity will probably be found to obtain in other allied 

 genera, while it occurs also in some Synallaxince. 



Within this cavity there will be found a strong buttress of 

 bony trabeculse for the inner head of the quadrate, in addition to 

 the usual orifices marking the apertures of the anterior, superior, 

 and posterior tympanic recesses, and the fenestrte rotunda and 

 ovalis. The superior and posterior tympanic recesses, it may be 

 remarked, are relatively small : in Artamia they can hardly be 

 traced while in Laniarius, ior example, they attain their maximum 



