392 DE E. W. SHUFELDT. 



it is not likely that many others will be added to them. These 

 genera are Aptenodytes, Eudyptes, Pygosceles, and Spheniscus. 



The work done by Professor Watson is so excellent and so 

 thorough that it leaves but very little to be said in the pre- 

 mises ; what he did, too, is based upon more ample material 

 than I have at my command at the present time, so that the 

 most to be set forth in this work are the main impennine osteo- 

 locfical characters which these birds exhibit, and which define 

 the group as a distinct suborder, as well as indicate, in so far 

 as their osteology is concerned, upon what the single family 

 Spheniscidm is based. 



The Skull. — Although possessing a number of characters in com- 

 mon, the skulls of these four genera named above are strikingly 

 different, showing a far greater difference, indeed, than do the 

 skulls of the representatives of different families, as they have been 

 defined for other avian groups. But Penguins possess many 

 very extraordinary characters in common, which characters are 

 not found in other birds ; and when this is the case, little regard 

 is paid to the variance among the skulls, and the forms are 

 commonly restricted to one family, with a few genera. 



In Aptenodytes the superior mandible is very long, narrow, and 

 tapering, being gently decurved distally. The sutures of the 

 elongated nasal bones are easily traced, and the proximal ends 

 of the nasal processes of the intermaxillaries are free and dis- 

 tinct. Long and narrow, either narial opening extends far 

 towards the mandibular apex. Upon the under side of this 

 beak there is a long mesial vacuity extending from the base of 

 the vomer behind to a point forwards opposite the anterior 

 terminations of the narial apertures. In Spheniscus the superior 

 osseous mandible is thick, and more or less massive like the rest 

 of the skull of this Penguin. It is in length but a little longer than 

 the cranium proper, and its apex is sub-abruptly deflected. From 

 side to side, it is more or less compressed anteriorly, while all 

 traces of the various sutures of the nasal bones are obliterated 

 in the adult. Viewing the cranium upon its superior aspect, 

 we find it flattened, and but moderately rounded off at the 

 sides. The fronto-interorbital space is never very wide, and 

 the large, superorbital glandular fossae are always conspicuously 

 developed. Posteriorly, in all Penguins the 'cerebellar prom- 



