to 



1898.] OSTEOLOGY OF BIRDS. 83 



what is found in the Storks and Herons, Procellarise, &c. The 

 2nd and 3rd are modifications of the 1st. 



The skull of the first type (PI. Yll. fig. 3) may be regarded as 

 typical of the Steganopodes, and is characterized as follows : — 

 " The palate is desmoguathous, the palatines are "broad, flattened, 

 and meet in the middle hne from the posterior narial aperture back- 

 wards to the pterygoids ; there is no vomer ; the maxillo-palatine 

 processes have become metamorphosed into a spongy mass fusing 

 with a much swollen nasal septum — similar to that of Balceniceps 

 —and not extending backwards into the lachrymo-nasal cavity as 

 usual, but yet preserving, as in P. carbo, a slight free posterior 

 border ; the orbital process of the quadrate is small, styliform, 

 placed at a right angle to the long axis, and about halfway do\\-n; 

 the anterior narial apertures are obsolete ; and the upper jaw 

 is more or less sharply defined from the skull by a fronto-nasal 



hinge. 



FhaUcrocorax and Plotus belong to this first type, and the 

 above description applies to both ; the points whereby the two 

 o-enera may be distinguished will be found in the appended " key." 

 It may be remarked here, however, that in Plotus the maxiUo- 

 palastine processes project backwards into the lachrymo-nasal 

 cavity as thin vertical laminae. There are two points, however, 

 wherein this family difi'ers from the others. Such are the presence 

 of a supraoccipitaf style and of a " suprajugular." The first is a 

 short, more or less triangular bony rod articulating with a small 

 tubercle on the supraoccipital : the second, as found m Plotus, is 

 a more or less elongated, oat-shaped lamina of bone, lying in the 

 lachrymo-nasal fossa, on the jugular process of the maxilla. It 

 was first described, many years ago, by Brandt (3), and appears 

 to have escaped the notice "of nearly every writer on the Osteology 

 of this group since. Mr. Beddard refers to it in his recent paper 

 in the P. Z. S. 1888 (1) ; Fiirbringer also refers to it (6). 

 Dr. Gadow writes me that he thinks it is probably " nothing 

 more than an additional splint-bone.'" I have been wondering 

 whether it is a remnant of a " maxillo-nasal " such as is described 

 and figured in the magnificent monograph on the Dinornithidae by 

 the late lamented Prof. T. J. Parker. In Plialacrocorax it is 

 represented only by alongneedle-lil^e splint. 



Our second type is found in the skulls of Phaethon and Pelecanus , 

 but, beyond this, the two skulls appear to have little else in 

 common. 



The skull of Phaethon (PI. YII. fig. 2) appears to De the least 

 specialized of the whole group, and presents characters which are 

 not only found in all, or nearly all the other Steganopodes, but 

 which also occur in forms outside this suborder. The most 

 important of these is the presence of a large tubular recess lying 

 immediately in front of the quadrate articular surface, and running 

 upwards between the squamosal and prootic bones. In it is 

 lodged the accessory bundle of the temporalis muscle. 



This recess is found in Sida and Fregata, where it is of con- 



6* 



