NATURAL SCIENCES OP PHILADELPHIA. 181 



looked at without seeing. This more than compensates for some 

 slight deficiencies that, under the circumstances, we could not 

 reasonably expect to find supplied. The article modestly pro- 

 fesses to be simply a museum catalogue, but it possesses scien- 

 tific claims of a very high order. The pterylographic data repre- 

 sent a valuable supplement to Nitzsch's earlier notice. So far 

 as we know, Prof. Hyatt is the first naturalist who has attempted 

 an}' critical discrimination of the various types of the Spheniscidse 

 with a view of determining their precise relationship, and espe- 

 cially their genetic relations to each other and to a probable an- 

 cestral stock ; and this, we need not add, is work upon a higher 

 plane than the mere identification of species, or preparation of 

 descriptions and synonymy. We must refer to the paper itself 

 for the details that we cannot here enter upon. It will suffice to 

 say here, in heartily indorsing the author's plan of study and 

 concurring in his general conclusions, that he shows better reasons 

 for the genera he adopts than any one has hitherto given, and that 

 our own studies of osteological structure, as far as these go, are 

 emphatic evidence in favor of his views. 



18*72. Giebel, Thesaurus Ornithologise, erster Halbband, 390. 

 In this work, an alphabetical catalogue of the nominal species, 

 thirty-one in number, that were originally described under "Ap- 

 tenodytes," is given, with the reference of each to its proper 

 place. The determinations seem to be correct, with few excep- 

 tions. As the work has not progressed beyond the letter U A," 

 the remaining names are not accounted for. 



II. ON CERTAIN POINTS OF CRANIAL STRUCTURE 

 BEARING UPON THE DETERMINATION OF THE 

 GENERA. 



Some authors have rested content with referring all the penguins 

 to a single genus, adopting either the name Aptenodytes or Sphe- 

 niscus; and there is some show of reason for this, in the fact that 

 all the representative species are singularly interrelated in various 

 points of form. But this is simply defining a genus upon the 

 identical grounds that indicate the family. Others, going to the 

 opposite extreme, have instituted or adopted a genus for every 

 leading species, though in so doing they have been of course un- 

 able to assign characters of more than specific value. To recon- 



