358 MR. W. p. PYCRAFT CONTRIBUTIONS [Apr. 9, 



the anterior palatal vacuity into right and left moieties. The 

 dorsal expanded plate, which gives the usual T-shaped form to the 

 mesethmoid, is here continued outwards and downwards in the 

 form of a small quadrate plate of bone depending from the mesial 

 border of the posterior region of the narial orifice. In Sayoi^nis^ 

 this ossification of the dorsal mesethmoidal plate extends the whole 

 way along the nasal process of the premaxilla instead of being con- 

 fined to a small area of the nasal orifice, but the lateral extension 

 of the plate so formed is not great, and is most noticeable near the 

 middle of the orifice. The median, vertical region of the septum 

 has its free edge expanded to form a narrow plate, grooved along- 

 its inferior surface down the middle line, and extending nearly 

 the whole length of the anterior palatal vacuity, the hinder end 

 of the plate being forked. And this obtains also in Contopus, 

 Tmniopterus, and Rhyncocyhclus — and doubtless in many other 

 genera. 



The Muscicapidse have a nasal septum agreeing in all respects 

 with that described as obtaining in Contopus and Sayornis for 

 example. In the Campophagidae, however, this septum is either 

 altogether absent, in the dried skin, or is represented only by a 

 feebly ossified ridge mmning down the inferior aspect of the 

 nasal process of the premaxilla. 



Among the Laniidse, as the group stands in Dr. Sharpe's 

 'Hand-list' (8), the Laniince agree with the Tyrannidse and 

 Muscicapidse in having the inferior border of the nasal septum 

 expanded by lateral flanges, but these are, in the group now 

 under discussion, very narrow. 



In Sphecotheres — which genus will be discussed in detail later 

 (p. 376) — the nasal septum is of this type. And the same is true 

 of the Prionopida?. In this family, however, secondary ossifi- 

 cation of the cartilaginous outer wall of the nasal capsule conceals 

 the septum from the inferior aspect of the skull. At first sight, 

 however, the existence of this floor beneath the septum would not 

 be suspected ; but rather it would be regarded as the septum 

 itself, which had developed unusually wide flanges, since it has all 

 the appearances of a septum such as occurs in the Tyrannida?, 

 differing therefrom, mainly, in being fused anteriorly with the 

 premaxillary palatal plate. 



In the Phytotomidfe, and in Corvinella *, Artamidse, and the 

 Gymnorhinfe among the Laniiform types, the wall of the vesti- 

 bulum is ossified ; and this in such a way that the postero-superior 

 angle of the normal narial aperture is cut off to form a slit-like 

 aperture, bounded mesially by the vestibular wall, and externally 

 by the descending process of the nasal. Traced backwards this slit 

 leads into the lachry mo-nasal fossa, and thence into the choange. 



The restricted narial aperture is small, and circular, owing to the 

 ossification of the cartilaginous nasal capsule — the vestilbulum. 

 It leads into a chamber, small in Artamia, large in Artamus 

 containing a well-developed concha media. This turbinal in 



* iMiiius exciihitor agrees with Corvinella in this respect and differs from 

 the remaining memhers of the senus. 



