210 PROCEEDINGS OF THE ACADEMY OP 



forked, rounded, or fan-shaped. Feet always tetra-dactyle, toiipalmate, hallux 

 dejyressed, lateral, long, functional. Bill wholly corneous, never lamellate; tomia 

 serrate or not ; its covering continuous or not, with or without a nail ; external 

 nares very small or abortive. A gular pouch. Tibia simple. Carotids double. 

 Desmognathous. Altrices. Ambulatorial, or scarcely so; generally powerful 

 flj-ers ; often good per chers ; urinatorial or not. Heavy, if not clumsy on land. 

 Insessorial Natatores. 



Ord IV. Lamellirostres. — Legs, as in Longipennes, near centre of equilihrium ; 

 position of axis of body in walking horizontal. Wings constant, moderate, 

 reaching to, but not bej'ond, the short rounded (exceptionally long cuneate) 

 many- feathered tail. Feet always tetradactyle, and palmate ; never totipalmate : 

 hallux elevated, moderate, free, simple or lobed, probably functional in all 

 cases. Bill lamellate, but tomia not serrate, covered with soft skin in greater 

 part, ivith more or less distinct nail at tip. Nostrils constant, well formed, latero- 

 superior, subbasal or median. No gular pouch. Tibia simple. Two carotids. 

 Desmognathous. Proecoces. Highly ambulatorial ; good flyers ; excellent swim- 

 mers ; poor divers. Heavy, though not clumsy, in either element. Cursorial 

 Natatores. 



The sequence of these orders is fixed. Pygopodes are first or lowest ; Lam- 

 ellirostres last or highest, beyond question. It might seem, on several accounts, 

 particularly position of legs, that Steganopodes should come next to Pygopodes. 

 But we cannot put anything between Longipennes und Pggojwdes, for they touch 

 if not inosculate at the points Halodroma and 3Iergulus. Moreover, other 

 ProcellariidcB have the long tibial apophysis that characterizes divers, but 

 disappears higher in the series. 



Families and subfamilies of PYGOPODES. 



The Penguins might be considered as presenting differences of more than 

 family grade ; they have been made a tribe or suborder [Impennes, Nullipennes, 

 Squamijyennes, Ptilopleri, auctt.) Thus they are unique in possessing no 

 remiges, scaly feathers, not entirely connate metatarsals, flat pterygoids and 

 arm-bones, and peculiar elbow-joint.* not to mention other lesser features. But 

 their characters are mostly of degree, not of kind ; and above all, the link 

 between them and Alcidx is so close and complete by ^4^c(7 ?wjoen?z/s, (extending 

 even to elbow joint and metatarsals) that the differences are really not so 

 great as appears at first sight. 



Three other families are not open to question. The four are thus distin- 

 tinguished, by external characters alone : 



Fam. Spheniscid.15. — Feathers scaly. No remiges ; wings useless for flight. 

 Hallux minute, elevated, lateral, functionless. Feet palmate. Tail many 

 feathered (with thirty or more rectrices, but sometimes fewer.) Usually with 

 modified feathers on head. Bill various. Altrices. 



I doubt there beihg two or more subfamilies ; that is, I think we must pass 

 directly to the genera (technically though one subfamily), all of which differ 

 from each other by characters of about the same value. The genera are few 

 — perhaps only two or three — based chiefly upon the bill and tail. These 

 birds are specially related only to the next. 



Fam. AhCiDAi.-f — Plumage normal. Remiges present, well developed (except 

 in one instance.) No hind toe. Feet palmate. Tail small, but definitely few- 

 feathered. Usually with modified feathers about head. Bill singularly various. 

 Altricial and Pra^cocial? 



Auks vary in details of form, particularly of the bill, with almost every 



• But I do not believe that either of the two little boues at the elbow of these birds, as 

 well as of Guillemots, represents a "detached oleocranou;" 1 hold them for true sesa- 

 moids, 



t Cf. writer's monograph Alcidie, Pr. A. N. S., Phila., 18U8. 



[Dec. 



