| OCR Text |
Show 1 9 0 6 . ] SELACHIAN FISHES. 7 43 any other Euselachii. The propterygium excludes the meso-pterygium from the margin of the fin. The mesopterygium is small and articulates directly with the pectoral arch, and most of the radials are attached to the metapterygium. In the Odontas-pididse the radials are simple, of moderate length and of comparatively few segments. In the Lamnidse (text-fig. 119, E) they Text-fig. 119. Skeleton of the pectoral fin of Mustelus (A), Pristiurus (B), Orectolobus (C), JELeptranchias (D), and Carcharodon (E). (A after Thacher, B and D after Gegenbaur, C and E after Has well). p, propterygium ; on, mesopterygium; mt, metapterygium. are composed of several segments, and extend to the free edge of the fin ; they show a tendency to bifurcate, whilst short distal intercalated cartilages are developed, recalling the structure of the pectoral fin in Cladoselachus. In the Scyliorhinidse and Carcha- |
