690 DR. p. CHAiiMERS MITCHELL ON THE 



tlie jugal below ; it lias a stout lamina projecting into the orbital 

 cavity transversely to the long axis of the skull and pierced for 

 the lacrymal canal. In the typical Storks and in Anastonms, 

 the external face of the lacrymal is roughly triangular, the convex 

 basal line being attached to the orbital edge of the frontal, but 

 definitely extending forwards across the hinge to form a very 

 loose connection with the nasal, not more than a fifth of the 

 whole dorsal edge of the bone. From this, the rapidly narrowing 

 triangle hangs down in front of the orbit and is far from reaching 

 the jugal and has no connection with the maxilla. The inwardly 

 projecting flange is a very thick beam pierced for the lacrymal 

 canal. In the Herons, the relations are a still further exaggera- 

 tion of the difi'erence between Storks and Balceniceps. The outer 

 surface of the lacrymal is triangular with a very broad base of 

 attachment to the frontal behind the hinge, a small loose overlap 

 to the nasal in front of the hinge, and with no connection with 

 j-Qgal or maxilla. The inwardly directed flange is absent and 

 there is no lacrymal canal. 



In the case of the lacrymal bone, therefore, Balainice'ps and 

 Ardea stand at opposite ends of a series, Tantalus being nearest 

 to Balceniceps. 



jVasal region. — The nostrils in Balceniceps are impervious, a, 

 stout nasal septum being developed. C4adow states that they are 

 pervious in Scopus, but this is a mistake ; a very thin lamina 

 of bone ver}^ slightly fenestrated separates them. In all the 

 Herons and Storks they are pervious, the cavity from one nostril 

 to the other being large and quite open. The skull is holorhinal 

 as in Scopus, Ardea, Cancroma and all the Storks including 

 Tccntalus, but in many, especially the larger Storks, the proximal 

 end of the nasal bone shows a line of weakness running up 

 towards the naso-frontal hinge and leading to the schizorhiny 

 seen in Ibis. From the anterior border of the nostril a groove 

 runs along the surface of the beak to the extreme anterioi- 

 end, only the hook of the beak projecting be3^ond it. Beddard 

 appears to lay some stress (4, p. 434) on this point because he 

 says that the groove is " precisely like that of Scojnts and Can- 

 croma." It is like that of Scopus, but in Cancroma the groove 

 is much wider a,nd more shallow and does not reach the extreme 

 anterior eiad. It is much more exactly repeated in the Pelican, 

 the Ibis and the Flamingo. In Ardea it is I'epresented by a groove 

 Avhich runs about half-way from the nostril to the anterior end 

 of the beak ; and in most of the Storks it is represented by a 

 line of weakness in the bone reaching about half-way to the tip 

 of the beak. This is specially well marked in Tantcdus. 



The nasal processes of the premaxillje are so firmly fused with 

 the adjacent nasals that their exact outline cannot be seen. It 

 is clear, however, that they do not invade the frontal region but 

 terminate distad of the fronto-maxillary hinge. This also is the 

 case in Cancroma, and Storks, including Tantalus, but in Ardea 



