SHUFKLDT : OSTEOLOGY OF THE STEGANOPODES 219 



As I have shown in this memoir all Cormorants possess a big patella. Mr. 

 Lucas in studying this bone has observed that this sesamoid in some of the species 

 is perforated for the passage of the ambiens muscle, while in others it is not so, but 

 this perforation is not associated with other characters in such a manner that the 

 condition can be regarded as having any taxonomic value. Mr. Lucas at my 

 request kindly examined this point for me in quite a number of species of Cor- 

 morants, and found that the patella is thus perforated for the ambiens in Graculus 

 Carbo, Phalacrocorax dilophus, P. vigua, P. harrisi, P. Magellanicus, P. albiventris, 

 (where it is small) and in P. pelagicus, while the patella is imperforate in Phalacro- 

 corax melanoleucus, P. pimctalus, P. penicillatus and P. urile. 



Osteologically, the Pelecanidse constitute quite a homogeneous group of birds, 

 and certainly a thoroughly circumscribed family of the Steyanopodes. I have ex- 

 amined the skeleton in several species, but more particularly in the case of Pelecanus 

 sharpei, P. fuscus, P. onocrotalus, and P. erythrorhynchus. In some species the mandi- 

 bles are broad and comparatively shorter than they are in others, and, when so, they 

 are compressed from above downwards. This is the case in P. sharpei (Plate VII., 

 Figs. 36, 37), and in this species we note in its skull that upon the lateral aspect of 

 the superior mandible, just where it is joined to the maxillary bone, the compact 

 tissue is continuous downwards to the anterior end of the corresponding palatine, 

 completely overlying and -concealing, on side view, the spongy tissue of bone in the 

 rhinal chamber, (Fig. 37). Whereas in such a species as P. fuscus there is a large 

 triangular interval left open here, so that upon the same view we are enabled to see 

 almost the entire mass of the osseous spongy tissue of the aforesaid space, (see Fig. 

 40 of my memoir, " Observations upon the Osteology of the Order Tubinares and 

 Steganopodes," Proc. U. S. Nat. Mus., 1888, p. 312). In the drawing referred to 

 the upper and lower edges of the united palatines have been shaved off, but I was 

 quite a juvenile osteologist when I prepared that specimen ; indeed it was my first 

 osteological preparation (1864). The correct form and outline of the lower united 

 edge of the palatine bones is shown in the case of P. sharpei in Plate VII., Fig. 37, 

 of the present memoir. In Figs. 35 and 40 of that plate I would say that the 

 horny podotheca covering the superior mandible of Pelecanus fuscus has only in part 

 been removed, and this also applies to the anterior two thirds of the mandible shown 

 in Fig. 41. Beyond what has been mentioned above, in most other respects, the 

 skulls of P. fuscus and P. sharpei are very much alike. 



In the mandible the ramal symphysis is, for the size of the bone, altogether the 

 weakest union of any in the entire Class Aves. For example, the ramus of the jaw 

 in P. sharpei has a length of 34.5 centimeters, while the symphysis joining the two 

 rami together, anteriorly, measures but 3 millimeters in any direction. 



