416 PEOE, T. JEFFEEY PAEKER ON THE CRANIAL OSTEOLOGY, 



deflected beak, constitute a very natural and highly specialized group. It may be 

 called the maximus-gro-aj), and, so far as I can make out, includes all the species placed 

 by Haast, Lydekker, and Hutton in the genus Dinornis, which name should therefore 

 be retained. 



2. A second highly specialized or culminating group is constituted by heavy-limbed 

 forms with strongly-built narrow skull, short broad beak, and stout mandible. This 

 may be called the crassus-group : its type species is also the type of Lydekker's Emeus. 

 I adopt this name. 



3. The remaining species together form a comparatively generalized group, including 

 forms of small or moderate height and of varying bulk, having narrow skulls and 

 pointed beaks. This assemblage is divisible into three subdivisions : — 



a. The elephantopns-growp, characterized by a larger and relatively broader cranium 

 than is possessed by either of the following groups, large temporal fossse, and a wide 

 V-shaped mandible. It corresponds with Lydekker's Pachyornis and with Haast's 

 Palapteryx, and is placed under Euryapteryx by Hutton. The name Fachyornis should 

 be retained, Palapteryx having been wrongly applied by Haast. 



h. The casuarina-gxonp, so-called from its type species. The skull resembles that of 

 the elephaniopus-grou]) in general features, but is smaller and more delicate, and has 

 considerably smaller temporal fossae. This section includes Hutton's Mesopteryx and 

 Cela, with part of Syornis ; it corresponds with Haast's Meionornis, with Eeichenbach's 

 Syornis, and with Lydekker's typical group of Anomalopteryx. Casuarinus being the 

 type species, Reichenbach's name has priority, but, as Lydekker has shown, it clashes 

 with Synornis of Hodgson. The group is certainly not congeneric with either the 

 preceding or the following one, and I therefore adopt Hutton's name Mesojiteryx, the 

 type species of which (didina) is here considered to be a variety of casuarina i. 



c. The didiformis-grouY>, in which parva, if really distinct, should be included. It is 

 characterized by an unusually straight beak and immense temporal fossse. This section 

 corresponds with Ano7nalopteryx of Reichenbach and Hutton, doubtfully with Haast's 

 Meionornis, and with Lydekker's Celine group of Anomalopteryx. There seems to be no 

 doubt that the name Anomalopteryx probably belongs to this group. 



I see no evidence favouring the retention of the genera Palapteryx and Cela. 

 Hutton retains Palapteryx for the reception of dromioides, Owen, and plena, Hutton, 

 the main ground of generic distinction being, as I understand, that the posterior view 

 of the skull of dromioides, as figured by Owen (17, pi. 54), shows an undoubted 

 approximation to that of Dinornis in its great relative breadth and short rounded 

 paroccipital processes. Lydekker, however, with the skull itself at his disposal, places 

 this species near casuarina. As to Cela, the type species is curta, of which oweni is, 

 according to Hutton, a synonym. Judging from Haast's figure of a fiagmentary skull, 

 I am disposed to agree with Lydekker in placing this species under Anomalopteryx. 

 ' Mec/alajjterijx probably belongs to this group. See Note above, p. 378.^June 1895. 



