I 



1894. THE WING OF ARCH/EOPTERYX. 441 



I have submitted it to my critics, trusting that it may lead to a 

 careful re-examination of the BerHn fossil, which, as I have previously 

 stated, I have never seen. 



Judging from Professor Seeley's description of this fossil (19), there 

 seems a possibihty that my rendering of the carpus may prove to be 

 correct. He pointed out that it was a moot point whether the 

 large free carpal described by Vogt belonged to the proximal or 

 distal row, and in the same paper he says : " The middle metacarpal 

 . . . so far as I can see, terminates proximally in a rounded 

 carpal bone like that of a bird " ; thus I imagine he believed, as I 

 do, that the bone in question represented the distal carpals, and not 

 the radiale, as Dames seems to think. 



There seems to be some difference of opinion as to the number 

 of phalanges in digit III., some describing three, others four. 

 Judging from the evidence of the wing alone, one would be inclined to 

 think that there were not more than three, and that the appearance 

 of four phalanges was due to the fact that the first phalanx of digit 

 III. had been snapped in two across its distal third, the dismembered 

 portion afterwards slightly drifting apart. Since, however, we get 

 precisely the same effect in both wings, this can hardly be deemed 

 the result of an accidental fracture ; though it is, perhaps, equally 

 hard to account for the fact that they happen to have separated in an 

 exactly similar way in each wing. Though this arrangement of a 

 short phalanx intercalated with two long ones is not unique, it cer- 

 tainly in this case appears in its most exaggerated form. 



Professor Dames has supplemented his description by an outline 

 restoration, Fig. 4 ; this, however, is probably not intended to do 

 more than represent in a very diagrammatic way the salient features 

 of the wing. It is strange, however, that he should have based this 

 restoration upon Gegenbaur's figures of the developing wing of an 

 embryo chick, since, as Dames himself shows, this eminent anatomist 

 was deceived as to the real nature of the avian embryo carpus. 

 In Gegenbaur's figure referred to, there is but one row of free carpals, 

 which represent the radiale and ulnare. The ulnare is of great size 

 and not only supports digits II., III., but contributes to that of digit I. 

 There is no indication of a distal row, for Gegenbaur believed that 

 at the time of the differentiation of the cartilaginous skeleton, only 

 the radiale and ulnare were present, and that, even in their beginnings 

 they showed no trace of fusion with other carpal elements. In 

 Dames' figure accordingly, the ulnare entirely supports digits II. 

 and III., while the radiale bears digit I. Thus the ulnare is much 

 larger than the radiale, whereas Dames laid great stress on the 

 large size of the latter of these two bones in the fossil ; so large, 

 indeed, did it appear to him there, that he imagined it must certainly 

 have afforded an articular surface for digits I., II., and perhaps even 

 III. It is probable that, in studying Gegenbaur's paper, the groove 

 across the " large free carpal," which he at first dismissed from con- 



