370 PROFESSOR OWEN ON THE GENUS NOTORNIS. 



the mandible: the upper surface of the symphysis (fig. 13, s) is deejily and almost 

 angularly excavated. The inner surface of the free portions of the rami is smooth and 

 gently concave, with a semicircular ridge extending from the anterior to the posterior 

 subcoronoid perforation. If the foregoing characters, of which the details will be ex- 

 cused from the rarity of their subject, be compared with those of the lower jaw of Por- 

 phyrio represented in figs. 1, 5, 6, PI. LVI., the correspondence will be found almost 

 perfect : the lower jaw of Porphyrio, however, is not a pneumatic bone and has no per- 

 foration for the admission of air. 



It is in the comparison of the lower jaw of the Notornis that the difference from the 

 Maccaw and the Raven, to which a passing reference was made in the description of the 

 upper jaw, is most strikingly seen. The mandible of the Raven is as much too shallow 

 as that of the Maccaw is too deep ; and in neither are the characters of the angle of 

 the jaw or the perforations repeated. And I may briefly state, that after passing in 

 review all the skulls and mandibles of the birds in the Hunterian and some other 

 Metropolitan collections, it is only in the Rallidte or the family of the Coots that I have 

 met with those essential marks of correspondence which have led to the determination 

 of the affinities of the bird to which the third remarkable fossil cranium in Mr. Mantell's 

 collection has belonged. 



Besides a species of true Porphyrio {P. melanotus, Gould) in New Zealand, there 

 exists in that island a peculiar and highly interesting form of the Rallida in which the 

 wings, although not so rudimentary as in the Apteryx, are nevertheless so restricted 

 in their development as to be useless for the purposes of flight. This bird is the type 

 of the genus Brachypteryx, — a genus as characteristic of New Zealand, as is the Apteryx 

 itself. In the lower jaw of the Brachypteryx we have the same form of the angular and 

 articular enlargement, with the vertical triangular posterior facet, the short deflected 

 and precurved angle, the posterior smaller and fuller oval perforation [w), and the 

 anterior fissure of the coronoid part of the jaw, but not the opening (m) : the symphysis 

 is shorter, but the rounded under-part ascends obliquely straight to the pointed termi- 

 nation of the mandible. There is the same kind of agreement in the upper jaw : the 

 solid or rostral part of which, anterior to the nostril, has the same essential form, viz. a 

 very slight and equable downward curve, gradually contracting to the point, which is 

 rounded ofl', while the sides are almost vertical. The palatine surface is deeply exca- 

 vated, but the lateral grooves are not defined as in Notornis. The differences between 

 the beak of this genus or of Porphyrio and that of Brachypteryx are those of proportion. 

 The whole beak is longer and more slender relatively to the cranium in Brachypteryx ; 

 and this length is gained by the elongation of the nasal part of the beak, or that which 

 is perforated by the external nostrils, and of the part between the coronoid portion and 

 the symphysis in the lower mandible. 



One may also follow minor traces of resemblance in the cranial part of the skull of 

 Brachypteryx, e. g. in the flat square formed by all that part of the basis cranii included 



