BIRDS WITH TEETH. 23 



ones only adhered to the skeleton. The theory of the nakedness of the body, as 

 advocated by Professor Vogt, is not very proliable, in view of the fact that the thighs 

 were feathered ; and to suppose that the rest of the body was scaly is liarcliy defen- 

 sible, for we may with greater right ask where the scales are than where the feathers. 

 Tlie eonehision we gain from the above is that the oldest bird known was a land- 

 liird, and arboreal in its habits. Hut in spite of its feathers it can hardly have had a 

 great resemblance to the forms which now inhabit the woods. Xor is it probable that 

 it was a very ex])crt flyer; the broad, rounded wings and the curious tail suggest a 

 locomotion of a somewhat similar nature to the 'flight' of the flying squirrel, tlie 

 tail of which in fact sti'ikingly recalls that of the Avchwopteryx. 



There have been and still are authors who regard this animal as a reptile, but 

 ajiparently with no good foundation. If we accept the theory that the birds have 

 develo))ed from the reptiles, the transition must have been gradual and nearly imjier- 

 ce]itible, so that the line to be drawn between the two classes must be more or less 

 artificial. But if we do not accept a feathered an<l warm-blooded vertebrate as a binl, 

 where then is the criterion to distinguish it from a reptile? 



The A rc/ia-opferi/x was long the only Jurassic bird known. In addilion to his 

 many other discoveries of fossil birds. Professor Marsh has of late added that of an 

 -Vmerican Jurassic bird, from the Atlantotiain-us-hcds of Wyoming, a form which in 

 ISSl he described as Laopten/x priscus. The most important s]iecimen is the poste- 

 rior portion of the skull, indicating a bird rather larger than a great blue Iieron. 

 Professor Marsh remarks further that in its main features the type specimen resembles 

 the skull of the Uatitie m<5re than that of any existing birds. In the matrix attached 

 to this skull a single tooth was found, which most resembles the teeth of birds, espe- 

 cially those of Ie/ilhi/07-nis ; and Marsh thinks it probable that it belonged to Laop- 

 terij.r, and that this bird also ])0ssessed biconcave vertebraj. Like Arc/iceopten/.i; it 

 was a land-bird. 



It wouM be futile to attempt a reconstruction of the wliole bird from the few 

 remnants on the old Cuvierian ]ilan, since modern discoveries have proved the utter 

 failure of the meth<id. Xobody can tell how the tail of Laoptirijx was formed, and 

 when we place it with the Saurune, we do so because that jiosition is as good as any 

 other, and because its geological age probably corresponds to that of Arclt/^opterifr. 



Leoniiaro Stk.ixeger. 



Sltb-Class II. — Odoxtotorm.e. 



Order I. — PTEROPAPPI. 



With the exception of the Soleidiofen bird, only a few scattered remains of fossil 

 birds, save from the most recent <leposits, had been found |>rior to those startling dis- 

 coveries which afterwards were fiirured and described in Professor Marsh's f.-mious 

 monograph on the extinct toothed birds of Xorth America. Xot only were the re- 

 mains of these cretaceous birds in an unusually sjilendid state of preservation, but they 

 reversed in many respects both the jiopular and the scientific ideas as to the charac- 

 ters and the origin of birds. 



As these Odontornilhes, or toothed birds, fomi one of the most interesting and 

 important contributions to mo(h'rn ornithological science, anil as a thorough \nider- 

 standins of their remarkable strucfui-e, so different from that of anv livins bird, is 



