Fig. 1. Transverse section through the pelvic fin of an embryo of
_Scyllium_ belonging to stage P[5], magnified 50 diameters. _bp._
basipterygium. _br._ fin ray. _m._ muscle. _h f._ horny fibres
supporting the peripheral part of the fin.
[Footnote 5: I employ here the same letters to indicate the
stages as in my "Monograph on Elasmobranch
Fig. 2. Pelvic fin of a very young female embryo of _Scyllium stellare_,
magnified 16 diameters. _bp._ basipterygium. _pu._ pubic process of pelvic
girdle (cut across below). _il._ iliac process of pelvic girdle. _fo._
foramen.
Fig. 3. Pelvic fin of a young male embryo of _Scyllium stellare_, magnified
16 diameters. _bp._ basipterygium. _mo._ process of basipterygium continued
into clasper. _il._ iliac process of pelvic girdle. _pu._ pubic section of
pelvic girdle.
Fig. 4. Transverse section through the ventral part of the trunk of an
embryo _Scyllium_ of stage P, in the region of the pectoral fins, to shew
how the fins are attached to the body, magnified 18 diameters. _br._
cartilaginous fin-ray. _bp._ basipterygium. _m._ muscle of fin. _mp._
muscle-plate.
Fig. 5. Transverse section through the ventral part of the trunk of an
embryo _Scyllium_ of stage P, in the region of the pelvic fin, on the same
scale as fig. 4. _bp._ basipterygium. _br._ cartilaginous fin-rays. _m._
muscle of the fins. _mp._ muscle-plate.
Fig. 6. Pectoral fin of an embryo of _Scyllium canicula_, of a stage
between O and P, in longitudinal and horizontal section (the skeleton of
the fin was still in the condition of embryonic cartilage), magnified 36
diameters. _bp._ basipterygium (eventual metapterygium). _fr._
cartilaginous fin-rays. _pg._ pectoral girdle in transverse section. _fo._
foramen in pectoral girdle. _pe._ epithelium of peritoneal cavity.
Fig. 7. Transverse section through the pectoral fin of a _Scyllium_ embryo
of stage P, magnified 50 diameters. _bp._ basipterygium. _br._
cartilaginous fin-ray. _m._ muscle. _hf._ horny fibres.
Fig. 8. Pectoral fin of an embryo of _Scyllium stellare_, magnified 16
diameters. _mp._ metapterygium (basipterygium of earlier stage). _me.p._
rudiment of future pro- and mesopterygium. _sc._ cut surface of a scapular
process. _cr._ coracoid process. _fr._ foramen. _hf._ horny fibres.
Fig. 9. Skeleton of the pectoral fin and part of pectoral girdle of a
nearly ripe embryo of _Scyllium stellare_, magnified 10 diameters. _mp._
metapterygium. _mes._ mesopterygium. _pp._ propterygium. _cr._ coracoid
process.