On the Pectoral Fin o/ Eustlionopteron. 471 



from C. britannicits, Verlioeff, and G. fri'suis, VevliocfF, both 

 of wliicii are not unconiiuou English species. However, 

 the gonopods, whicli are figured by Biolernann and Verhoeff 

 {loc. cit.), are quite definite diagnostic characters, and so 

 there is no doubt about the record. Ouv material bears these 

 numbers :— 1379, 1380, 1381, 1382, Brade-Biiks collection. 



Eeference. 



(i) BuoLEMANN, IT. W., aiid C. W. Verhoeff. "Matdriaux pour 

 survir a une fniuie dos Myriapodes de France." Feuille des 

 Jeiines Natiirulistes, Sept. 1896, uo. 311, pp. 214 et seq., with 10 

 text-liss. 



XLVIII. — Note on the Pectoral Fin o/'Eu'^tlienopteron. 

 By Dr. Branislav Petronievics. 



The pectoral fin of Eusthenopteron was figured and described 

 for the first time by Whiteaves (comp. J. F. Wiiiteaves, 

 1889, p. 87, & pi. V. fig. 5), who^e description was improved 

 by Traquair (comp. K. H. Traquair, 1890, |). '19). Two 

 other specimens of the same fin were figured by A. S. Wood- 

 ward (1898, p. 25) and W. Patten (1912, p. 391). 



During my stay in London this year tiie ])ecforal fin in 

 tlie British Museum specimen P. (5796 of Eustlienojyteron^ 

 figured by A. S. Woodward (whose figure was republished 

 by E. S. Goodiich in 1902, pi. xvi. fig. 1), was sumcwhat 

 newly ])repared by Mr. F. O. Barlow. I give here a new 

 figure of it (comp. text-fig. 1) and a brief description. 



Tiie pectoral fin in our specimen is composed (1) of an 

 axis, (2) of preaxial radials, and (3) of postaxial processes. 



Tlie axis consists of four pieces. The first or basal piece is 

 situated behind the dis[)laced cleithrum, of which the inferior 

 edge lies near to its superior edge in the specimen. It is not 

 possible to decide whether this elongated and somewhat 

 obscure bony matter is to be identified wholly with the basal 

 piece of the fin, or whether it does not comprise also the 

 coraco-scapular ossification. Should this latter be the case, 

 then the front edge of the postradial process of the basal 

 would mark the limit between the basal and coraco-scapula. 



The second piece of the axis is expanded and slightly 

 bifurcated posf>eriorly. The third piece is somewhat longer 

 than the second and expanded still more posteriorly, where it 

 lias not only a large postaxial process, but is also more 

 distinctly biiuicatod. 



